[Plugin: Nextgen gallery] slideshow blank in firefox

Slideshow is the reason I want this fab plugin, but my slideshow doesn’t work in Firefox; there is just a black screen with the loading animation. It diaplays perfectly in IE and Opera. It neither works on the page or in the slideshow widget, it just hangs there however I try to use it. I’ve done a fair bit of reading and although I found this:-

Q/ I can’t see the thumbnails in FireFox , Internet Explorer show them correct.

A/ This is an open CSS issue. Please have a look in your theme style-sheet and search for max-width: 100%;
Delete this line and the thumbnails are shown also in FireFox.

in the faq for the plugin, the solution doesn’t work for me as there is no max-width: 100% anywhere I can find. I don’t get any error messages at all. Anyone else have this problem? I love this plugin but if it wont play nicely with Firefox I can’t keep it.

I’m running:- WordPress 2.5.1
Nextgen Gallery 0.98

I’m not very tech savvy so you’ll probably have to keep it simple

Thanks in advance!