I had an NT 4.0 BDC. We were running out of space on the 80 gig drive, keep in mind this is entirely NT 4.0. So after the complete backup ran on fri night. I did a restore to the new Windows 2000 Advanced Server, which was added as a member server. The data is accessed globally so a lot of people access it. We had all Domain Local Groups set up for each directory (..read, ...write, etc). So when the restore completed I verfied the permissions on each share and they matched those on the old server. Monday morning anyone in the Domain Local groups could not access any data. There are a few global groups flying around, and they can access the data. So I removed one of the domain local groups from the directory permissions and went to re add it and noticed that I could not see any of the domain local groups. Then I tried to add the permissions to the share from the PDC and it alos wouldn't bring up the domain local groups on that share on the Windows 2000 Server.
Next I went and checked our other NT 4.0 member servers and they also could not see the Domain Local Groups. So after checking our other NT servers, the only ones that would allow permissions to on shares to Domain Local groups were those on NT BDC's or PDC's.
I don't ever remember learning anything about that.