"Boot Error" message when booting Ubuntu 9.10 from USB sticks (Occurs only on 1 PC)
Solution 1:
Turns out it really was corrupt, it also stopped working on the other computers.
For some reason it seems that USB installs of Ubuntu are really fragile and break easily for some odd reason. Is the MBR of a USB stick overly sensitive or something, makes me wonder. So people, back-ups!