It's the classic Australian TV problem - channels running over time.
The only real way to do it with 2 tuners is to set an advanced record & set hard padding (stop after 5, 10, 15 mins etc.) - remeber though that the VMC will pinch the tuner you're using for live TV for the second recorder.
Once you get a second HVR-2200, you can set priorities for different tuners (whether they should be normally used for live or recorded TV & in what order).
Justin