If you are on the new alpha track via the UI that is the newest version.....
Not sure why that is happening. I haven't seen that although I usually back out of Recorded TV HD when I'm finished out of habit. I just asked my wife and she said that she will leave it on Recorded TV HD often when turning off the TV and she doesn't recall that happening.
Not sure if I should open a new thread, but I am experiencing this 100% of the time. Just as you described. If I back out to Media Center and power off the TV, everything is fine the next day. If I leave it in Recorded TV HD then turn off the TV the next morning the system is hung and I have to kill eshell to get back in.
This happens to me three to four times a week. MJT previously believed it to be related to having many Unidentified Files of types other than WTV. At this point, I don't have any Unidentified Files and it still occurs for me. You might want to make sure you don't have any Unidentified Files. If it's still an issue after that, then MJT may need to pursue this further for you/us.
On my HTPC, after around 6 - 8 hours, WMC becomes unresponsive. Using RTVHD, I'll be watching a recorded show and the remote as well as the wireless keyboard no longer work. I can't stop, pause or automatically skip commercials. I occasionally get a message that RTVHD has quit working. If I get the message and resume the show from RTVHD everything is again fine. If not, I'll have to wait until the show has ended and get back the remote and keyboard. I'll then close WMC, reopen it, and everything is again fine.
Same with me, Cruising. This happens to me at least a few times a week and unidentified files aren't an issue. Fortunately, I can generally alt-cntrl-del to task manager and then exit WMC. A lot of times when I'm in the process of starting up task manager is when I get the message that the program is not responding and needs to close. TBH, though, I don't remember if it tells me that RTVHD is not responding or if it says WMC. I'll pay more attention next time it happens. I'm also on WIN 7 and the latest alpha.