Reports missing users

I’m experiencing a strange User Manager problem where reports don’t include some users. It looks like the missing users are quite random - after deleting some old and inactive users User Manager suddenly stopped including additional users in the report.

I tried to recreate the database and reboot, but nothing helps.
Software version is 6.32.2 (latest).

Any ideas anyone?
This adds to some other instability issues I’ve experienced with User Manager which make me wonder whether or not User Manager is stable and reliable enough (which is a pity for me).

I usually make a backup before any changes to userman.
I think backup via console is better than UM interface backup.

Issue is fixed in v6.33rc33

*) userman - fix report generation problem which could result in some users being skipped from it;