My computers are running windows xp pro SP2. On any computer if uPNP is enabled in my network places it causes the explorer window to "hang". When I restart the computer I can open my network places only once, after closing it any additional attempts to open it fail "double click absolutely nothing happens". If I go into control panel and remove uPNP it works fine. The dilemma is I need uPNP because I have a network of about five systems and manual routing sucks. Also, I have noticed my icons on the system tray sometimes do not all appear when I boot and uPNP is enabled.