Help needed with login problem

[M. G. Hand]

I need some clues to help me solve the following problem.
When I log out of a certain application program i am only
able to log back in again using logins for which there is
no password set up.  If i try to use a login with a password,
I always get "login incorrect" WITHOUT being prompted for the
password.  It is several hours (>1 probably <3) before the
login sequence returns to normal.

Unix release 5.3, ATT 3B5, (1.2 hardware upgraded).

Thanks in advance for any useful pointers.

		Marcus Hand   (pyuxt!marcus)