My XL4 has spontaneously rebooted 4 times in the last six weeks and under the exact same conditions. On a Sunday I will be recording an early NFL game on one tuner and a second and later NFL game on second tuner and a different channel. While watching the first game I press the left arrow on the Select Pad to go back to the menu and the screen goes black and the TiVo XL4 reboots and then resumes recording the two games.
I was using the SD menu during above incidents, which brings me to another problem I encountered. Again using the SD menu I was watching a show I had recorded a few days earlier when I began to get artifacts, pixilation and sound distortion. Iíve encounter this before but it only lasted for a few seconds, but this time it continued for several minutes until I gave up on the recording. Out of curiosity I changed to the HD menu interface and went back to the supposedly corrupted recording and now it played perfectly. One of the things I checked when I encountered these problems was to see if the TiVo was perhaps recording 4 things and was overloaded, but in each case there was never more that 2 red lights indicating a recording in progress.
Iíve owned TiVoís for about 12 years and I was pleased that TiVo gave me the option to use the SD menu as I found the HD menu to be some what sluggish while responding to the remote. I am starting wonder if using the SD menu contributing to my problems.