Had the same problem last Saturday. Sat and resized almost 40 photos, and NOT ONE took. Sigh. I use Firefox as well.

There is a free software mentioned in this thread where I posted asking for help, check into that! See post 10 specifically, AND Phred's caution right after.

http://petoftheday.com/talk/showthread.php?t=140843

I haven't had a chance to try it as yet.