the internet is a fickeled thing ! You can download PingPlotter. Its a free program you can use to check your connection through the internet. Install it and then use the addresses Skuzzy has posted in the sticky at the top of the thecnical Support thread. Then run the ping for 15 minutes or so pinging every 5 seconds.
This will show you the route, and the time in milliseconds to the HTC servers and back. Anything under 200 is "sweet" and the lower the better. More important is "steady" with no packet loss. Also, you and your "buddy" might be routed throught the same node on the internet, when it craps out, or dumps you to save bandwidth like Comcast has been doing, you'll both get loose your connection, so it "could" be your ISP.