I was also having a similar problem and here is the solution I ran accross while looking through the Apple mailing list for Mac OS X Server.
Check out http://kbase.info.apple.com/cgi-bin/WebObjects/kbase.woa/wa/query?type=ids&keyword=&daysWithin=&val=106570&x=54&y=12
Knowledge Base...
I am running Mac OS X Server 10.1.1 on a Powermac G4. With the built in Windows File Service enabled, no guest access, no WINS Registration, and no Master or Domain Master Browser enabled I consistantly get the following error:
[2001/12/07 09:51:49, 0]...