SAM replication problems with PDC

Recently we deleted a user account from our NT 4.0 SP6a Primary Domain Controller, as the user had left the company. Upon the next syncronization attempt of our BDC, the Event Log on the BDC reports “Replication of SAM User “Rid: 0x3f8” with primarydomain controller failed with the following error; Specified group does not exist. The PDC reports the following at each replication attempt, “This server service was unable to map error code 1797” Any Ideas what could be causing the problem?