Since 9.1 upgrade, my S3 has rebooted twice during primetime!

I put my Series 3 on the priority list for the 9.1 update. It installed fine, no problems like others have reported, and it upgraded a couple of days ago.

Since then, my S3 has exhibited the same behavior two consecutive nights during prime time, both while recording two HD shows:

- It will stop outputting any video to the TV screen.
- The front display will still show the shows being recorded, and the clock will advance. The orange light on the front will blink when the remote is used, but otherwise the TiVo is nonresponsive (will not power off, for example).
- After about 5-10 minutes in this state, the S3 will reboot.

An examination of the leftover recordings seems to indicate that the TiVo was still recording when it was nonresponsive.

I find this rather suspicious that this happened RIGHT AFTER the 9.1 update. When I called TiVo support, they suggested trying to record without CableCards; if that worked then they told me get new CableCards. If it still crashed without CableCards then I should get a new TiVo. I don't mind trying to record stuff without CableCards, but exchanging the TiVo is really a last resort for me.

Is anyone else experiencing this kind of problem? I am willing to believe new software triggered a dormant hardware problem. I am also willing to believe that with the new fall shows all in HD I filled up the disk enough to hit a bad spot. Does anyone have any suggestions as to what the problem might be?