Try it with virtualbox 1.6 and if it still doesn't work you should report it at the link mentioned by Erik.
** Changed in: ubuntu Status: New => Invalid -- gutsy alternate in virtualbox cannot install bootloaders https://bugs.launchpad.net/bugs/138889 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs