The issue is that Firefox tries to draw a progressbar of very small size (width=1, height=1). This results in a negative object allocation in cairo, which makes it eat all the memory.
** Attachment added: "stack trace with symbols" http://librarian.launchpad.net/6383736/bt.txt -- ubuntulooks causes massive memory use at startup for Firefox 3 trunk build https://launchpad.net/bugs/84221 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
