Non Administrative users unable to log in to console

Hi,

I have run into a problem that any non administrative user
is unable to log into one of our XP pro machines. the
system bule screened and the end user had to press the
reset to bring the machine back up after that when any non
admin user receives the following message when they try to
log in;
your account is configured to prevent you from logging
into this computer. please try another computer.

I have tried to change the passwords on the affected
accounts and even having a blank password. none of that
worked. I have tried changing the affected accounts from
power user to administrator and then the system allows
them to log in.
Is there anything I can do short of reinstalling the whole
system?

Thanks in advance.
Matt