Problems installing Parallels VMs on MBA 2012

Ubuntu and Windows 8 preview are giving me grief on my new MBA. I use Windows 7 Bootcamp to feed one VM, and have a couple of others for WinXP. I installed Ubuntu 11.04 from scratch and that worked, but when I attempt to upgrade to 11.10 it just boots to the grub menu and any choice from that menu results in a reboot. If I choose "previous versions" and choose one from there, it works.

The Windows 8 preview downloaded, but goes into an infinite reboot loop. I've updated Parallels to the latest version.

Any ideas?