[Samba] NetBIOS Nameresolution

[gerd at bugri.com]

I have installed a new Win 2003 Applicationserver in a Network with Samba 
2.2.1a as PDC. Some clients are not able connect to the Server by entering 
"\\s-003" into Explorer. When i sniff the Network i can see that NetBIOS 
Name Resolution doesn't work properly. They get as a response to a name 
querry to the PDC a wrong Ip-Address back!!
Does anybody know how this can happen and where Samba gets the information 
about NetBIOS names and the corresponding IP-Address from?
Looking forward to any hints, Gerd