linux-image-2.6.20-4-generic fixes the lockup. Thanks! That kernel's postinst script is buggy though, but that's a different issue...
** Changed in: linux-source-2.6.20 (Ubuntu) Status: Confirmed => Fix Released -- Kernel hangs late in the boot process https://launchpad.net/bugs/76204 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs