Users get password failures on thin clients but not server console

[Rob Shugg]

Hey
We had a power failure at the school and since then users get an
incorrect password error when logging in either from the thin client
or from gdm on the server- in this setup there are only four terminals
- three TC's and the fourth is the actual server.

The odd thing is that when i log on the the console on the server I
get no password error and i can then log in to gdm after <cntrl> <alt>
<F7>.

Where should  I start on this?

edubuntu 6.10

Rob