Darn. Okay, I also made a mistake. Let me set the stage (all references to speeds are upload): Server machine runs uTorrent on 14555. Desktop machine was running it on 7999. Set QoS on 14555, all of a sudden uTorrent on the server started working. Set QoS on 7999, desktop was still goofy. Changed desktop port to 14556, it started working, too. Forgot to change QoS from 7999 to 14556. So the desktop has been working normally on 14556 for apparently no reason. Tonight I'm doing some more testing, speeds unrestricted. I'm finding that if I launch the desktop, and wait for it to update all the peers, it works fine - until I also launch the server app, and even though these are running on different ports. After I launch the server, the server upload is nil, and the desktop upload drops from about to 8Kbps (from about 150Kpbs at the time, but obviously upload speed is variable based on demand). As soon as I kill the server, the desktop jumps right back up to normal speed. Doing this the other way around: launch the server first, port 14555. I have good upload, but it took a while for the peers to find me and ask. Launch the desktop - upload speed tanks. Kill the desktop, upload speed returns. Here's the kicker though. That's with QoS off. I'm going to leave QoS off for a while, and see what happens. I'm still not convinced that QoS has nothing to do with it, at least for where I'm at (Chicago market). I imagine it's possible that there's some kind of ignore timer that hasn't run out on me yet.