Here is a simple solution that works very well for me:
You dont have to use UPnP or install any other Bit Torrent client. For me, Bit Tornado is always the best.
1. Open Bit Tornado. Go to Prefs.
2. Use only 1 port in the port range. Set both the From and To box to the same port and DISABLE randomize.
3. Set the UPnP Port Forwarding to Disabled.
4. If you use a router, make sure you set the router to forward this port to your computer.
That's it! You're done.
I'm using Windows XP SP2 and Bit Tornado works extremely well on my computer. When I open a torrent file, Bit Tornado connects instantly to the tracker and I get the green light after only 2 seconds. Download speed is always at least 100 kB/s and upload at maximum capacity.
DON"T BOTHER-you will only be able to open one instance of your client. Otherwise you would have to have each instance set at different port. Not worth the time it takes.
UPnP? I have 10000 ports (range) available, randomized, with UPnP set to fast, max 60 connects, & UPnP is totally disabled in services. I don't have a router but I know alot of people have probs setting one up with port forwarding. Thing is, if you can't connect you have to (learn).
http://portforward.com/routers.htm
No AV-get real