I can’t disable Virtual Share Points?

I have an Xserve which I've setup as a PDC. I've read that virtual share points can cause problems. The problem is that I can't disable the "Enable virtual share points" within the Windows settings. Every time I uncheck the tick box and click save it reappears, it doesn't matter whether the Windows service is running or not? I thought that it may be a bug with Mac OS X 10.4.8, but I updated to 10.4.10 last night and I'm still having the same problem. Is there a line in smb.conf that I can edit in order to force the removal of virtual share points? Any help or ideas on this one would be much appreciated. Thanks.