Need help: How to connect to a workgroup in Ubuntu

Hello there

First I have to tell that I’m new to Linux… Recently I installed Ubuntu 5.10 on a workgroup PC (P3, on board network adapter), everthing went smooth, after installing I configured the Hostname, IP, Subnet and gateway in the networksetting and even activated the connection

But I cannot see any other PC in the workgroup (all the other clents are Win Xp).. But I can Ping to some of the clients not all
I don’t have even the internet connection…..

I guess that I’m not connected to the workgroup properly
can anyone please help me with this

Tank You
Frank