kdesktop_lock does not accept password

Fri Oct 21 10:59:20 UTC 2005

I installed Kubuntu 5.10 preview and have updated the system to all current
packages.

Since the last update yesterday I cannot login after locking the desktop.
kdesktop_lock does not accept the password and says:

Oct 21 12:34:19 KUMMEROG unix_chkpwd[4909]: check pass; user unknown
Oct 21 12:34:19 KUMMEROG kcheckpass: (pam_unix) authentication failure; logname=
uid=1000 euid=1000 tty=:0 ruser= rhost=  user=tk23279
Oct 21 12:34:19 KUMMEROG kcheckpass[4908]: Authentication failure for tk23279
(invoked by uid 1000)

What is the the problem here? What has changed?

Regards
Thorsten