mouse and keyboard gone

[Roger Searle]

Hadn't planned to start the week like this . . .   Last week I plugged 
in a different (USB) mouse to this box, a much more comfortable one than 
the existing PS2 one.  I looked for a close listing in Control Centre - 
I forget which I ended up choosing, the closest match for 3 buttons with 
wheel (though think I had to go with 2 button). 

Starting the computer again this morning I find that neither the 
keyboard nor mouse will function.  Powering down, plugging the old mouse 
back in and restarting does not help - the keyboard did function at the 
point of selecting a boot option in grub. 

Booting to failsafe mode allows me to log on and do startx, however a 
desktop will not load - it hangs on a "blue screen" (just a desktop 
background) without presenting any icons.  On attempting to run sax2 it 
says that an x server isn't running so will start one if necessary 
(which it then proceeds to attempt to do), and similarly hangs 
presenting a blue background.

I'm stuck at this point - any suggestions for me to try that doesn't 
involve getting out the install disk to "repair/reinstall"?

Cheers,
Roger