This is not the first report about Admin Console showing bizarre groups information in Users/Groups list. This user reports, that for some users it shows a number of groups, when in reality in the database their only have one or few groups.
I wonder if this commit is to blame for all these troubles
Was this resolved in 4.1.2 (is this a duplicate of )?
These tickets sounds similar, so i'm going to mark this as fixed also. But this one is only when Admin Console shows wrong information (rosters in clients are ok). The other one is when users can't see members of other groups.