Thanks for the info...I've updated the firewall and LW to use specific ports for each computer.

However, I still see the same symptoms I mentioned previously, where having ALL ports open for the PC gives me a 'Full Connection' in LW, but as soon as I restrict it to the PC-specific port along with 6436 I only get a 'Medium Connection', and I've noticed on occassion that I lose the connection all together for periods of time, whereas with all ports open the connection stays full, all the time.

I see BitTorrent ports (6881 to 6889) listed in the Tools | Options | Advanced --> Listening Ports options. Do these need to be open on the firewall as well and/or are there any other ports that need to be open to get a 'Full Connection'?