I am also having the same problem, I am using the flash 9 beta and I think that is causing the problem... So I don't know if this is a "firefox" bug per say...
** Attachment added: "crash report" http://librarian.launchpad.net/5053741/_usr_lib_firefox_firefox-bin.1000.crash -- Crash on firefox close https://launchpad.net/bugs/58457 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
