Ok, I'll give that a go. However I don't seem to have a grub.conf file there, or anywhere according to the output of locate! I do have a file called menu.lst there if that's any use? That seems to store the details of what shows on the grub menu, along with some other elements...
Edit: That seems to have worked (when I figured out what I was supposed to be doing). So I guess this indicates there's a problem with the "nvidia" drivers in console mode maybe?
I also still can't ctrl+alt+F1 into a console from the desktop