First id like to say that you did an excilent job makeing this app, i was about to make a similar one outa frustration of not being able to find a tool with sufficent flexability.
After some tinkering my friend and i got our game to work right, all was well untill one or both of our routers would stop responding and lock up. With a quick reset it would continue and all was well for 30secs to even 5 min untill one of our routers would lock again. It doesnt always freeze completly, sometimes just the internet on our computers stop working completly, because i can usually remote connect to his dlink and reset it and its up and going again in a few secs. We have tried about every possible way of configuring stuff that i can think of. Useing UDP was the only way it worked, had mixed results with tcp, how it connect for a time. Hard to troubleshoot the problem when somenoes router is going out ever 1min or so. Both on cable connection and routers, linksys(me), and a dlink. Maybe we are doing something to flood it? im not too sure, hopeing u have an insite to what this may be. I also get alot of unforwarded dump in my logs, much more than sent recieved.. 3x more or so. We are both on 192.168.0.xxx and no conflicting ips on the network, and same mask 255.255.255.0 .