all the nightly builds of firefox just crashes at startup. not even profile manager. build 2004-03-09-17 crashes build 2004-02-28-08 works Windows XP - SP2
Marking as a duplicate; i suggest you download a newer build a see if it still happens. *** This bug has been marked as a duplicate of 236673 ***
The fix was checked in just now. It might be in today's nightly build, but will certainly be in tomorrow's.