Not scrolling

[Tim Day]

Hi there,
The Grub bootloader is really handy but I have encountered a problem. My 
system is using Ubuntu 10.04. For some reason I cannot scroll through 
the OS selection table using the arrow keys. This just started today and 
it was working before. I have been installing and un-installing some 
software today including gtkpod, hipo and floola trying to get my iPod 
loaded with music without resorting to Windows.
This means that I cannot make my computer boot to anything but the 
default, even if I change the boot priorities in the BIOS.
Any ideas? Is this a bug. I understood that GRUB is not dependent on the 
OS so I should not be able to damage it.
Regards,
Tim Day