Firefox 3 loses ability to save

This seems random but maybe not. I’ll have Firefox 3 (3.0.6) open and, at the beginning, it’ll save files fine. But, seemingly all of a sudden, I can’t save. It goes into save mode, shows me the file name and I browse to my location and click save but then nothing happens and nothing appears in the save location or on my downloads list. A quick google doesn’t find a wide-spread application problem so it may be something I’m doing.

Windows XP SP3

Thoughts or ideas greatly appreciated.