Problemer med centreret hjemmeside ved brug af Thickbox

Hej Eksperter,

Jeg er rendt ind i et problem, når jeg laver en hjemmeside med centreret indhold, og laver et link til Thickbox css-filen vises siden ikke længere centreret, men venstre justeret. Problemet opstår kun i Firefox og Google Chrome. Den vises fortsat korrekt i Explorer.

Her vises siden korrekt:
http://www.logeroyal.dk/thickbox/ctest1.php

Men når jeg inkluderer linket til css-filen, går det galt:
http://www.logeroyal.dk/thickbox/ctest.php

css-filen ser ud som følger:

/* ----------------------------------------------------------------------------------------------------------------*/
/* ---------->>> global settings needed for thickbox <<<-----------------------------------------------------------*/
/* ----------------------------------------------------------------------------------------------------------------*/
*{padding: 0; margin: 0;}

/* ----------------------------------------------------------------------------------------------------------------*/
/* ---------->>> thickbox specific link and font settings <<<------------------------------------------------------*/
/* ----------------------------------------------------------------------------------------------------------------*/
#TB_window {
    font: 12px Arial, Helvetica, sans-serif;
    color: #333333;
}

#TB_secondLine {
    font: 10px Arial, Helvetica, sans-serif;
    color:#666666;
}

#TB_window a:link {color: #666666;}
#TB_window a:visited {color: #666666;}
#TB_window a:hover {color: #000;}
#TB_window a:active {color: #666666;}
#TB_window a:focus{color: #666666;}

/* ----------------------------------------------------------------------------------------------------------------*/
/* ---------->>> thickbox settings <<<-----------------------------------------------------------------------------*/
/* ----------------------------------------------------------------------------------------------------------------*/
#TB_overlay {
    position: fixed;
    z-index:100;
    top: 0px;
    left: 0px;
    height:100%;
    width:100%;
}

.TB_overlayMacFFBGHack {background: url(file:///C|/Users/AppData/Local/Microsoft/Windows/Temporary%20Internet%20Files/Content.IE5/87F5Q9CX/macFFBgHack.png) repeat;}
.TB_overlayBG {
    background-color:#000;
    filter:alpha(opacity=75);
    -moz-opacity: 0.75;
    opacity: 0.75;
}

* html #TB_overlay { /* ie6 hack */
    position: absolute;
    height: expression(document.body.scrollHeight > document.body.offsetHeight ? document.body.scrollHeight : document.body.offsetHeight + 'px');
}

#TB_window {
    position: fixed;
    background: #ffffff;
    z-index: 102;
    color:#000000;
    display:none;
    border: 4px solid #525252;
    text-align:left;
    top:50%;
    left:50%;
}

* html #TB_window { /* ie6 hack */
position: absolute;
margin-top: expression(0 - parseInt(this.offsetHeight / 2) + (TBWindowMargin = document.documentElement && document.documentElement.scrollTop || document.body.scrollTop) + 'px');
}

#TB_window img#TB_Image {
    display:block;
    margin: 15px 0 0 15px;
    border-right: 1px solid #ccc;
    border-bottom: 1px solid #ccc;
    border-top: 1px solid #666;
    border-left: 1px solid #666;
}

#TB_caption{
    height:25px;
    padding:7px 30px 10px 25px;
    float:left;
}

#TB_closeWindow{
    height:25px;
    padding:11px 25px 10px 0;
    float:right;
}

#TB_closeAjaxWindow{
    padding:7px 10px 5px 0;
    margin-bottom:1px;
    text-align:right;
    float:right;
}

#TB_ajaxWindowTitle{
    float:left;
    padding:7px 0 5px 10px;
    margin-bottom:1px;
}

#TB_title{
    background-color:#e8e8e8;
    height:27px;
}

#TB_ajaxContent{
    clear:both;
    padding:2px 15px 15px 15px;
    overflow:auto;
    text-align:left;
    line-height:1.4em;
}

#TB_ajaxContent.TB_modal{
    padding:15px;
}

#TB_ajaxContent p{
    padding:5px 0px 5px 0px;
}

#TB_load{
    position: fixed;
    display:none;
    height:13px;
    width:208px;
    z-index:103;
    top: 50%;
    left: 50%;
    margin: -6px 0 0 -104px; /* -height/2 0 0 -width/2 */
}

* html #TB_load { /* ie6 hack */
position: absolute;
margin-top: expression(0 - parseInt(this.offsetHeight / 2) + (TBWindowMargin = document.documentElement && document.documentElement.scrollTop || document.body.scrollTop) + 'px');
}

#TB_HideSelect{
    z-index:99;
    position:fixed;
    top: 0;
    left: 0;
    background-color:#fff;
    border:none;
    filter:alpha(opacity=0);
    -moz-opacity: 0;
    opacity: 0;
    height:100%;
    width:100%;
}

* html #TB_HideSelect { /* ie6 hack */
    position: absolute;
    height: expression(document.body.scrollHeight > document.body.offsetHeight ? document.body.scrollHeight : document.body.offsetHeight + 'px');
}

#TB_iframeContent{
    clear:both;
    border:none;
    margin-bottom:-1px;
    margin-top:1px;
    _margin-bottom:1px;
}