usrmgr.exe. When logged in as root, trying to assign rights to users fails, access denied.
LDAP backend(other backends not tested).
If you cant reproduce i'll get traces/tcpdumps soon.
log level 10:
User rights assignment should be fine in master and v3-4-test now, can you please test ?
Fixed for next Samba 3.2 release (by reverting to previous behaviour).