I had the same problem the other day. Go in to the security applet, firewall settings and loosen up the File & Print Sharing option, also loosen up ICMP inbound aka PING, then PING 19.. etc and do a \\192..\share etc to get the login prompt

Secure by design.. Cool

Rob Atkinson
Kilkenny, Ireland
blog: http://spaces.msn.com/knowledgebyte