I can contribute this link* which seems the same problem in i945. According freedestkop's bug, the issue is solved, at least in development branch.
*https://bugs.freedesktop.org/show_bug.cgi?id=9686 -- Maps disappearing when zooming in on google earth https://launchpad.net/bugs/90622 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
