I've had that happen quite a few times.
I've also had the "out of phase" audio when switching screens. It's an annoying intermittent issue, but I resolve it by just pausing the broadcast, pressing the TiVo button to go back to the home screen, then going back to the program I was watching, and its fine.
The other issue I have is where my 2 HD's don't see the Premiere, but the Premiere can see the HDs. Again, it just "goes away" after a few days.
I just don't have the patience to deal with support because all they are going to do is "make a trouble ticket". I always just assumed it was one of those "things" you just deal with. I have called with numerous technical issues over the years, and all it does is amount to frustration because there are no advanced technical people there who can look into the back end to reolve issues like these. All they have ever done is called me or e-mailed me back after a few days and offered to exchange my box for a fee. Ridiculous.
TiVo Premiere XL4 (2 of 'em!)
TiVo Mini (Codename: UNICORN)
Retired: TiVo Series 2 ST, Philips Series 1 HDR212