I bought a fit-pc slim a while ago, but could not install it untill a couple of days back. Did not really have any time to spend on something like this. Anyway, i was installing Ubuntu 8.10 Server, and hit a bug in the Ubuntu installation.
I was installing the OS on a USB Flash drive since i want the box to be stable and not use a lot of power.
When Ubuntu 8.10 writes down the grub mbr, it will not overwrite the mbr if grub is already installed. I dont know if this is the case in other versions of Ubuntu. However, you will not have this problem if you have a fresh USB Flash drive without a mbr written, but if you have used the Flash drive for some other installation before.
To fix this I booted the system on a bootable GRUB CD and rewrote the mbr from the GRUB shell/OS.
If you don’t know how to do this there is a bootable superGRUB image that can be installed on USB Flash, Floppy or CD-ROM. It has some fancy menus that will guide you through different processes. If you want to learn more about GRUB it is also a great resource to just start up and play around with.
I believe SuperGRUB can be found at http://www.supergrubdisk.org/