I gave up! I have a linux box that can see the W7 PC and share the printer connected to the W7 PC. I can see the recorded tv folder on the w7 PC and watch stuff on my linux box but I cant access the My Documents folder on the w7 PC. The w7 PC sees nothing but itself on the network whether I am part of a home group or not. I also have a laptop WXP that can share the printer but not access folders.
So I will watch this thread with great interest to see if a solution is forthcoming!