Hi All, Now I drove to the "missing group site" to see the things with my own eyes.
I found out a slight detail that affects the case :-). In addition to the three WS2003 DCs, there were also some NT4 BDCs left. So the problem of where the missing groups existed turned out to have quite an obvious solution... (Actually, a little too obvious, because we all missed it. Not that I can blame anyone, because I told you that the the problem domain has three DCs, and I should have known about the NT4 ones...) Two things remained a mystery, though. A) Why they had disappeared from the WS2003 DCs in the first place. My guess is that because a replication issue they didn't replicate out of the upgraded PDC before those guys removed and formatted the upgraded PDC. (this I already knew but forgot to include in the case description of my previous message, sorry) They did check that replication was ok, before they removed the DC, though. B) From the in-place upgrade in July until last week (about six weeks, that is) the groups still existed in the NT4 BDC, although NT replication should have removed them. So why didn't this work. My guess is a WINS (or name resolution) problem, so that the NT4 BDCs didn't find their new PDC (emulator). Yours, Sakari PS. Even thought the explanation turned out to be quite obvious, this was still an interesting case. List info : http://www.activedir.org/List.aspx List FAQ : http://www.activedir.org/ListFAQ.aspx List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/
