Ahh sorry - my bad. I just re-read your initial post, and saw it was an upgrade. For some reason I thought you were dual-boot using the F9 grub.
You can probably safely ignore all that I said above.
I have managed to kind of boot the OS by changing the partition that is loaded in GRUB.
You want to explain that some more - in detail ?.
Sounds like an X issue - but you should still drop to a (nash ?) shell that allows you to do (limited if nash) commands.
More detail needed