Windows On Mac :: Network Lost In Vista After Afk?

I have a 2.8GHz alu iMac running vista 32-bit through the latest version of bootcamp. All the latest drivers updates etc. are installed.

Today I was downloading a torrent using μTorrent. After I started it I left the computer running, my connection was fine at that point, as it usually is. When I came back (it didn't go to sleep), around 250mb had downloaded but it had since stopped. I saw that I didn't have a connection. I tried searching for networks, but the computer couldn't find any, which is strange since it normally finds around 6-7 networks, including my own. I ran network diagnostics, which told me there might be problem with the computers network adaptor or something, and that I had to connect it and then try again. I had no idea what that means, so I logged off and on to see if that solved the problem, it didn't. I restarted to OSX and my network was fine again. When I restarted again in vista it was still fine, so the problem was gone. I would like to know what exactly went wrong though, and whether it had to do with the torrent or not. I've left the mac running on vista while I was away before, and this has never happened.