lightbox: css override by unknown element.style

Hi, I’m using lightbox (jquery-lightbox-balupton-edition) in combination with NextGen Gallery.
Everything wordks fine, except one little thing.

I want the background to be 100% white, i don’t want opacity.

I’ve tried to fix it in de css, but some element is overriding my code.
I can see the element with firebug:
<div id=”lightbox-overlay” style=”width: 1215px; height: 7117px; display: block; opacity: 0.9;”>

BUT I CAN’T LOCATE IT. Its driving me mad.

Does anyone have an idea?

THANX!!

Pices of the jquery.lightbox.css:

#lightbox, #lightbox-overlay {
position: absolute;
top: 0px;
left: 0px;
bottom:auto;
right:auto;
opacity: 1;

z-index:100;
width:100%;
height:auto;

text-align:center;
color:#333333;

/* stop stupid conflicts */
margin:0px;
padding:0px;
border:none;
outline:none;
line-height:0;

/* general conflict stopper */
text-decoration:none;
background:none;
word-spacing:normal;
letter-spacing:normal;
float:none;
clear:none;
display:block;
}

#lightbox-overlay {
z-index: 90;
background-color:#fff;
height: 100%;
-moz-opacity: 1;
opacity:1;
filter: alpha(opacity=100);
;