We have one site currently testing Samba 3.0.21c as PDC on HP-UX 11.00 with OpenLDAP. Since their migration to Samba, they regularly cannot logon to NT4 SP6a workstations, because the logon prompt immediately returns after typing in username and password, without any error message at all. After restarting the NT workstation, logging on works again. Their XP workstations do not have this problem. The problem appears identical to the one described in http://support.microsoft.com/?scid=kb;en-us;220881 but the solution given there does not help. To me this seems to be an NT4 bug, because the workstation does not even seem to try to contact the domain controller (the logon prompt returns really instantly after clicking OK). But before migration (from ASU) to Samba, they did not have this problem, so it does seem Samba related somehow. BTW the NT4 machines were not changed in anyway for the Samba migration. Any ideas? Thanks.