Swapping Tuners on the Comcast DCH3416 Digital Video Recorder

If you are a Comcast Cable subscriber that has the DCH3416 DVR (check the front right of your DVR) you may be confused as to how to watch one TV program while recording another. On the remote control there is a small button on the bottom called "Swap". What that button does is let you switch between the 2 TV Tuners built into the DCH3416 DVR. For example, I may set E.R. to record, but want to watch Lost instead. The DVR will automatically ask if I would like to swap tuners, or continue watching the channel I'm on when a recording is started. I choose to switch tuners so that my recording starts. But now I want to get back to watching Lost. This is where I can hit the "Swap" button on the remote and go back to the other tuner. I can then change channels as I please while E.R. records. The Tuner that reads REC on the front display is recording, the other Tuner that you swapped to displays TV channels.