The only variable between your setup and mine, then is the source of our wifi connection. Since you can't test your setup with my tablet, and vice versa then we might have to assume that it's the wifi gateway that's inhibiting the connection, which seems kind of odd that your gateway would inhibit that extra connection since it's not really an extra computer that's connected, but just a different video source.
Do you have access to any other HTC device like your cell phone that you can test the connection? Have you or anyone adjusted the settings on the wifi modem? I'll perform another retest with a longer running video, but I don't appear to be experiencing the same issues. One more test you can attempt with your wifi modem is to disconnect all other devices that are typically connected to the modem and connect just your tablet to the wifi.