I think I managed to successfully backtrace X via ssh from another machine. The wiki doesn't explain how to attach Valgrind to an already running process though, so you'll have to talk me through that if you need Valgrind for X.
** Attachment added: "gdb" http://librarian.launchpad.net/4794782/gdb-X.txt -- edgy: ooffice crashing x https://launchpad.net/bugs/64013 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs