Desperate, HELP! Keyboard quits working on login
So, on an elderly family member's computer, the keyboard stops working after one has logged, ie entered username and password. It doesn't matter what sort of keyboard, ps/2 or USB. The family member swears they did not mess with anything, and I believe them, because all they ever do is web surfing and word processing.
I "clean' installed their system to the latest kubuntu, gutsy, with clean in quotes cos I retained their home partition. The problem persists. So, it seems likely (to me, I may be wrong) the problem is in some configuration file in the home partition. I'm presuming it is NOT a hardware problem since it persists with multiple keyboards plugged into multiple ports, and since the keyboard works fine when booted to a live cd, or up until login.
The family member is getting antsy for me to fix this, my post asking for help in the kubuntu forums has gone ignored, and every google search I've done gives me no clues as to what files that would be in the home directory would mess up the keyboard, all keybard config files reside in directories other than home, according to every page google's given me that seemed applicable. I've got no clue here. Help!