User can't login after backup script

Hi,
we have JazzTeamServer 4.0 (RTC,RQM,RRC(all 4.0)), recently upgraded from 3.0.1.2
If we reset password to our user, he can't login next day (during night, there is backup script). We don't use LDAP, user data are stored in tomcat-users.xml.
The only similiar error in logs is: (in jazz.log)
2012-12-11 03:01:36,187 [jazz: AsynchronousTaskRunner-3] ERROR com.ibm.team.repository - CRJAZ2388E Error encountered when synchronizing user data between servers in the background. The synchronizer will silently continue to attempt to synchronize the data.
Any ideas?
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EDIT:
Backup script "timeline" (suspend indexer, stop server, do backup, start server, resume indexer)
(after backup script, there is still running old java process although ./server.shutdown was called)
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Thanks
Comments
Karl Weinert
JAZZ DEVELOPER Dec 12 '12, 10:52 a.m.How do you resolve the issue?
What database are you using and is that being stopped during the backup as well?
If so make sure it gets restarted before RTC
How are you resetting the password?
Matus Gura
Dec 12 '12, 4:26 p.m.We are using IBM DB2. Yes, it's being restarted during backup, when JTS is turned off. We are reseting using web UI (we tried also Eclipse client). I tried @bkchulin idea, I am waiting for colleagues feedback