PC1 does ask for a logon so I followed your first link, which led back to a Microsoft KB article. One of the suggested items to look at was if TweakUI had been installed. Sure enough I had put that on several months ago, played around with it, and then forgot I had it installed. To solve the problem all I had to do was reenable Network Neighborhood in TweakUI. What's that saying about a little knowledge...?
Thanks for your quick response,