I doubt that the new backtrace is more useful, but now Firefox directly crashes opening that page: http://www.tagesschau.de/video/0,1315,OID6421744_RES_NAV_BAB,00.html (German sadly). ticking "Windows Media" and clicking on "Video starten".
I will attach it, following https://wiki.ubuntu.com/MozillaTeam/Bugs, though. ** Attachment added: "gdb firefox 2nd backtrace" http://librarian.launchpad.net/6453722/gdb-firefox.log -- Firefox crashes after watching embedded video https://launchpad.net/bugs/85112 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs