My settings are the same as yours except that I don't have public folder sharing turned on and don't have a Homegroup. Just for grins I did a Shutdown rather than a Restart on my Win 7 laptop. When I powered back up again the Windows Home Server was back in the Network list but the XP laptop (that I had changed from cable connected to Wi-Fi connected as an experiment) was not. I had not changed any of the Advanced Sharing Options.
I just checked the Home Theater PC (Win 7). It had been Restarted because of updates. The Windows Home Server is back in its Network list but the XP laptop is not. Guess I'll change the XP laptop back to cable connection and see if it reappears.
This is what drives me crazy. The problem seems to be random and arbitrary. It must have something to do with whether or not I am wearing socks when I restart my laptop.
Yep, after I changed the XP laptop back to a cabled connection it reappeared in the Network list on my Win 7 laptop.