Link: http://www.stillbelieving.net/gallery2/
My custom theme is set to default and it will not show in all browsers.
Shows in : Internet Explorer
Doesn't show in: Safari
Ah never mind.
No idea what I did, and I swear I did nothing, but it works now.
Try to validate your HTML output: http://validator.w3.org/check?verbose=1&uri=http%3A%2F%2Fwww.stillbelieving.net%2Fgallery2%2F
Your output is invalid, that's a possible reason why it doesn't display as expected on all platforms.
Please resolve your threads in the future as suggested per board rules (http://forum.coppermine-gallery.net/index.php/topic,55415.msg270631.html#msg270631). I did that for you now.