I am running WinXP SP2 and, until earlier, VMWare Server 1.0. However, since I installed VMWare Server last week, utorrent would fail to map a UPnP port to my router. I even downloaded a special UPnP test program from http://www.junegillespie.plus.com/UPnPTest.exe which would promptly fail. As an experiment I made one system change - I uninstalled VMWare Server, and UPnP started to work again.
Anyone else come across this issue? Any idea what I can do to get these two apps to co-exist? Note that even utorrent 1.6 (which doesn't use UPnP) won't work for me if VMWare Server is installed.