Pues ya intenté todo y sigo viendo igual el foro :S
. Dejo, el global.css.
body {
	background: #000000;
	color: #FFFFFF;
	text-align: left;
	line-height: 1.4;
	margin: 0px 0px 0px 0px;
	padding: 0px;
	
	font-family: Arial, Helvetica, sans-serif;
	font-size: 12px;
}
a:link {
	color: #FFFFFF;
	text-decoration: none;
}
a:visited {
	color: #FFFFFF;
	text-decoration: none;
}
a:hover, a:active {
	color: #FFFFFF;
	text-decoration: none;
}
#container {
	background: #141414;
	color: #626262;
	margin: auto auto;
	padding: 20px;
	text-align: left;
}
#content {
	width: auto !important;
}
.menu ul {
	color: #000000;
	font-weight: bold;
	text-align: right;
	padding: 4px;
}
.menu ul a:link {
	color: #000000;
	text-decoration: none;
}
.menu ul a:visited {
	color: #000000;
	text-decoration: none;
}
.menu ul a:hover, .menu ul a:active {
	color: #4874a3;
	text-decoration: none;
}
#panel {
	background: #efefef;
	color: #000000;
	font-size: 11px;
	border: 1px solid #D4D4D4;
	padding: 8px;
}
table {
	color: #000000;
	font-family: Verdana, Arial, Sans-Serif;
	font-size: 13px;
}
.tborder {
	background: #0a0a0a;
	width: 100%;
	color: #626262;
	margin: auto auto;
	border: 1px solid #1c1c1c;
}
.thead {
	background: #0c0c0c url(mybbvn/lighting/images/menu_b.png) repeat-x top left;
	color: #626262;
	border: 0px solid #1c1c1c;
	
	font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif;
	font-size: 10pt;
	font-style: bold;
}
.thead a:link {
	color: #626262;
	text-decoration: none;
}
.thead a:visited {
	color: #626262;
	text-decoration: none;
}
.thead a:hover, .thead a:active {
	color: #626262;
	text-decoration: underline;
}
.tcat {
	background: #171717;
	color: #626262;
	border-top: 1px solid #1c1c1c;
	
	font-family: tahoma, verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif;
	font-size: 11px;
	font-style: bold;
}
.tcat a:link {
	color: #626262;
}
.tcat a:visited {
	color: #626262;
}
.tcat a:hover, .tcat a:active {
	color: #626262;
	text-decoration: underline;
}
.trow1 {
	background: #1d1d1d url(mybbvn/lighting/gradients/gradient_alt1.gif) top left repeat-x;
	color: #ffffff;
	border: 1px solid #1c1c1c;
	border-width: 0px 1px;
}
.trow1 a:link {
	color: #6699cc;
	text-decoration: none;
}
.trow1 a:visited {
	color: #6699cc;
	text-decoration: none;
}
.trow1 a:hover, a:active {
	color: #6699cc;
	text-decoration: underline;
}
.trow2 {
	background: #191919 url(mybbvn/lighting/gradients/gradient_alt2.gif) top left repeat-x;
	color: #ffffff;
	border: 1px solid #1c1c1c;
	border-width: 0px 1px;
}
.trow2 a:link {
	color: #6699cc;
	text-decoration: none;
}
.trow2 a:visited {
	color: #6699cc;
	text-decoration: none;
}
.trow2 a:hover, a:active {
	color: #6699cc;
	text-decoration: underline;
}
.trow_shaded {
	background: #ffdde0;
}
.trow_selected td {
	background: #FFFBD9;
}
.trow_sep {
	background: #e5e5e5;
	color: #ffffff;
	font-size: 12px;
	font-weight: bold;
}
.tfoot {
	background: #1b1b1b;
	color: #626262;
	padding: 10px;
}
.tfoot a:link {
	color: #626262;
	text-decoration: none;
}
.tfoot a:visited {
	color: #626262;
	text-decoration: none;
}
.tfoot a:hover, .tfoot a:active {
	color: #626262;
	text-decoration: underline;
}
.bottommenu {
	background: #1d1d1d;
	color: #000000;
	padding: 10px;
}
.navigation {
	color: #626262;
	font-size: 13px;
}
.navigation a:link {
	color: #626262;
	text-decoration: none;
}
.navigation a:visited {
	color: #626262;
	text-decoration: none;
}
.navigation a:hover, .navigation a:active {
	color: #626262;
	text-decoration: none;
}
.navigation .active {
	color: #626262;
	font-size: small;
	font-weight: bold;
}
.smalltext {
	font-size: 11px;
	color: #ffffff;
}
.smallfont {
	color: #ffffff;
	font-size: 11px;
}
.largetext {
	font-size: 16px;
	font-weight: bold;
}
input.textbox {
	background: #ffffff;
	color: #000000;
	border: 1px solid #0f5c8e;
	padding: 1px;
}
textarea {
	background: #ffffff;
	color: #ffffff;
	border: 1px solid #0f5c8e;
	padding: 2px;
	line-height: 1.4;
	
	font-family: Verdana, Arial, Sans-Serif;
	font-size: 13px;
}
select {
	background: #ffffff;
	border: 1px solid #e8fdff;
}
.editor {
	background: #f1f1f1;
	border: 1px solid #ccc;
}
.editor_control_bar {
	background: #fff;
	border: 1px solid #0f5c8e;
}
.autocomplete {
	background: #fff;
	border: 1px solid #000;
	color: black;
}
.autocomplete_selected {
	background: #adcee7;
	color: #000;
}
.popup_menu {
	background: #ccc;
	border: 1px solid #000;
}
.popup_menu .popup_item {
	background: #fff;
	color: #000;
}
.popup_menu .popup_item:hover {
	background: #C7DBEE;
	color: #000;
}
.trow_reputation_positive {
	background: #ccffcc;
}
.trow_reputation_negative {
	background: #ffcccc;
}
.reputation_positive {
	color: green;
}
.reputation_neutral {
	color: #444;
}
.reputation_negative {
	color: red;
}
.invalid_field {
	border: 1px solid #f30;
	color: #f30;
}
.valid_field {
	border: 1px solid #0c0;
}
.validation_error {
	background: url(images/invalid.gif) no-repeat center left;
	color: #f30;
	margin: 5px 0;
	padding: 5px;
	font-weight: bold;
	font-size: 11px;
	padding-left: 22px;
}
.validation_success {
	background: url(images/valid.gif) no-repeat center left;
	color: #00b200;
	margin: 5px 0;
	padding: 5px;
	font-weight: bold;
	font-size: 11px;
	padding-left: 22px;
}
.validation_loading {
	background: url(images/spinner.gif) no-repeat center left;
	color: #555;
	margin: 5px 0;
	padding: 5px;
	font-weight: bold;
	font-size: 11px;
	padding-left: 22px;
}
/* Additional CSS (Master) */
img {
	border: none;
}
.clear {
	clear: both;
}
.hidden {
	display: none;
	float: none;
	width: 1%;
}
.float_left {
	float: left;
}
.float_right {
	float: right;
}
.menu ul {
	list-style: none;
	margin: 0;
}
.menu li {
	display: inline;
	padding-left: 5px;
}
.menu img {
	padding-right: 5px;
	vertical-align: top;
}
#panel .links {
	margin: 0;
	float: right;
}
.expcolimage {
	float: right;
	width: auto;
	vertical-align: middle;
	margin-top: 3px;
}
img.attachment {
	border: 1px solid #E9E5D7;
	padding: 2px;
}
hr {
	background-color: #000000;
	color: #000000;
	height: 1px;
	border: 0px;
}
#copyright {
	font: 11px Verdana, Arial, Sans-Serif;
	margin: 0;
	padding: 10px 0 0 0;
}
#debug {
	float: right;
	text-align: right;
	margin-top: 0;
}
blockquote {
	border: 1px solid #ccc;
	margin: 0;
	background: #fff;
	padding: 4px;
}
blockquote cite {
	font-weight: bold;
	border-bottom: 1px solid #ccc;
	font-style: normal;
	display: block;
	margin: 4px 0;
}
blockquote cite span {
	float: right;
	font-weight: normal;
}
blockquote cite span.highlight {
	float: none;
	font-weight: bold;
	padding-bottom: 0;
}
.codeblock {
	background: #fff;
	border: 1px solid #ccc;
	padding: 4px;
}
.codeblock .title {
	border-bottom: 1px solid #ccc;
	font-weight: bold;
	margin: 4px 0;
}
.codeblock code {
	overflow: auto;
	height: auto;
	max-height: 200px;
	display: block;
	font-family: Monaco, Consolas, Courier, monospace;
	font-size: 13px;
}
.subforumicon {
	border: 0;
	vertical-align: middle;
}
.separator {
	margin: 5px;
	padding: 0;
	height: 0px;
	font-size: 1px;
	list-style-type: none;
}
form {
	margin: 0;
	padding: 0;
}
.popup_menu .popup_item_container {
	margin: 1px;
	text-align: left;
}
.popup_menu .popup_item {
	display: block;
	padding: 3px;
	text-decoration: none;
	white-space: nowrap;
}
.popup_menu a.popup_item:hover {
	text-decoration: none;
}
.autocomplete {
	text-align: left;
}
.subject_new {
	font-weight: bold;
}
.highlight {
	background: #FFFFCC;
	padding: 3px;
}
.pm_alert {
	background: #bbf9ff;
	border: 1px solid #FFD324;
	text-align: center;
	padding: 5px 20px;
	
	font-size: 11px;
}
.red_alert {
	background: #FBE3E4;
	border: 1px solid #A5161A;
	color: #A5161A;
	text-align: center;
	padding: 5px 20px;
	font-size: 11px;
}
.high_warning {
	color: #CC0000;
}
.moderate_warning {
	color: #F3611B;
}
.low_warning {
	color: #AE5700;
}
div.error {
	padding: 5px 10px;
	border-top: 2px solid #FFD324;
	border-bottom: 2px solid #FFD324;
	background: #FFF6BF;
	font-size: 12px;
}
div.error p {
	margin: 0;
	color: #000;
	font-weight: normal;
}
div.error p em {
	font-style: normal;
	font-weight: bold;
	padding-left: 24px;
	display: block;
	color: #C00;
	background: url(images/error.gif) no-repeat 0;
}
div.error.ul {
	margin-left: 24px;
}
.online {
	color: #15A018;
}
.offline {
	color: #C7C7C7;
}
.pagination {
	font-size: 11px;
	padding-top: 10px;
	margin-bottom: 5px;
}
.tfoot .pagination, .tcat .pagination {
	padding-top: 0;
}
.pagination .pages {
	font-weight: bold;
}
.pagination .pagination_current, .pagination a {
	padding: 2px 6px;
	margin-bottom: 3px;
}
.pagination a {
	border: 1px solid #81A2C4;
}
.pagination .pagination_current {
	background: #F5F5F5;
	border: 1px solid #81A2C4;
	font-weight: bold;
}
.pagination a:hover {
	background: #F5F5F5;
	text-decoration: none;
}
.thread_legend, .thread_legend dd {
	margin: 0;
	padding: 0;
}
.thread_legend dd {
	padding-bottom: 4px;
	margin-right: 15px;
}
.thread_legend img {
	margin-right: 4px;
	vertical-align: bottom;
}
.forum_legend, .forum_legend dt, .forum_legend dd {
	margin: 0;
	padding: 0;
}
.forum_legend dd {
	float: left;
	margin-right: 10px;
}
.forum_legend dt {
	margin-right: 10px;
	float: left;
}
.success_message {
	color: #00b200;
	font-weight: bold;
	font-size: 10px;
	margin-bottom: 10px;
}
.error_message {
	color: #C00;
	font-weight: bold;
	font-size: 10px;
	margin-bottom: 10px;
}
.post_body {
	color: #FFFFFF;
	padding: 5px;
}
.post_content {
	padding: 5px 10px;
}
.quick_jump {
	background: url(images/jump.gif) no-repeat 0;
	width: 13px;
	height: 13px;
	padding-left: 13px; /* amount of padding needed for image to fully show */
	vertical-align: middle;
	border: none;
}
.mybbvn_wrapper_t {
 background-image: url(mybbvn/lighting/images/wrapper_t.png); background-color: #141414; background-repeat: repeat-x; background-position: top left;
}
.mybbvn_wrapper_b {
 background-image: url(mybbvn/lighting/images/wrapper_b.png); background-repeat: repeat-x; background-position: bottom left;
}
.mybbvn_wrapper_l {
 background-image: url(mybbvn/lighting/images/wrapper_l.png); background-repeat: repeat-y; background-position: top left;
}
.mybbvn_wrapper_r {
 background-image: url(mybbvn/lighting/images/wrapper_r.png); background-repeat: repeat-y; background-position: top right;
}
.mybbvn_wrapper_tl {
 background-image: url(mybbvn/lighting/images/wrapper_tl.jpg); background-repeat: no-repeat; background-position: top left;
}
.mybbvn_wrapper_tr {
 background-image: url(mybbvn/lighting/images/wrapper_tr.jpg); background-repeat: no-repeat; background-position: top right;
}
.mybbvn_wrapper_bl {
 background-image: url(mybbvn/lighting/images/wrapper_bl.jpg); background-repeat: no-repeat; background-position: bottom left;
}
.mybbvn_wrapper_br {
 background-image:url(mybbvn/lighting/images/wrapper_br.jpg); background-repeat:no-repeat; background-position:bottom right; padding: 40px 80px 170px 80px;
}
.mybbvn_header {
	position: relative;
	padding-top: 150px;
}
#logo_image {
 position: absolute; top: 30px; left: 0px; margin: 0px;
}
#logo_banner {
 position: absolute; top: 60px; right: 10px; margin: 0px;
}
#mybbvn_date {
	color: #FFFFFF;
	position: absolute;
	top: 10px;
	left: 10px;
	margin: 0px;
}
.mybbvn_menu_portal {
 background-image: url(mybbvn/lighting/images/menu_m.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_portal:hover {
 background-image: url(mybbvn/lighting/images/menu_level1_item.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_portal_selected {
 background-image: url(mybbvn/lighting/images/menu_level1_item.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_forum {
 background-image: url(mybbvn/lighting/images/menu_m.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_forum:hover {
 background-image: url(mybbvn/lighting/images/menu_level1_item_blue.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_forum_selected {
 background-image: url(mybbvn/lighting/images/menu_level1_item_blue.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_calendar {
 background-image: url(mybbvn/lighting/images/menu_m.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_calendar:hover {
 background-image: url(mybbvn/lighting/images/menu_level1_item_green.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_calendar_selected {
 background-image: url(mybbvn/lighting/images/menu_level1_item_green.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_member {
 background-image: url(mybbvn/lighting/images/menu_m.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_member:hover {
 background-image: url(mybbvn/lighting/images/menu_level1_item_orange.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_member_selected {
 background-image: url(mybbvn/lighting/images/menu_level1_item_orange.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_help {
 background-image: url(mybbvn/lighting/images/menu_m.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_help:hover {
 background-image: url(mybbvn/lighting/images/menu_level1_item_pink.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.mybbvn_menu_help_selected {
 background-image: url(mybbvn/lighting/images/menu_level1_item_pink.png); background-repeat: repeat-x; padding-left: 12px; padding-right: 12px; height: 30px;
}
.leftbox {
 background-color: #1a1b1a; border: 1px; border-bottom-style: solid; border-color: #232323; text-align: left; padding: 4px; margin-bottom: 4px;
}
.inside {
 color: #6699cc; font-weight: bold;
}
.dgreybox {
 display: block;
}
.dgreybox * {
 display: block; height: 1px; overflow: hidden; font-size: .01em; background: #1B1B1B;
}
.dgreybox1 {
 margin-left: 3px; margin-right: 3px; padding-left: 1px; padding-right: 1px; border-left: 1px solid #282828; border-right: 1px solid #282828; background: #212121;
}
.dgreybox2 {
 margin-left: 1px; margin-right: 1px;padding-right: 1px;padding-left: 1px;border-left: 1px solid #303030; border-right: 1px solid #303030; background: #1f1f1f;
}
.dgreybox3 {
 margin-left: 1px; margin-right: 1px;border-left: 1px solid #1f1f1f; border-right: 1px solid #1f1f1f;
}
.dgreybox4 {
 border-left: 1px solid #282828; border-right: 1px solid #282828;
}
.dgreybox5 {
 border-left: 1px solid #212121; border-right: 1px solid #212121;
}
.dgreyboxfg {
 background: #1B1B1B;
}
.alt_forumlar {
list-style: none; margin: 0; padding: 0;
}
.alt_forumlar li {
width: 50%; float: left;
}