Ghost : modify all 'width: 500px;' in the CSS file. It must be the maximum width of yours photos. I think it should be ok. Thanks for using it. If it doesn't works, tell me, i will try on my site with larger pictures (mines are 500px, no more).
Errrwin : i just saw the problem with Firefox 1.5. I will try to fix it (
i hope, i don't know how i can change it !?)... in few days, because lot of work this week end.