My 721 has been running fine for about 5 months now. I reboot it every week or whenever it seems to be pissy about recording. Well... Last night at 3 am I got up to let my dog out. I noticed the green power light was flashing. I held down the power button to reboot the machine. I went back to bed and when I got up this morning they screen said something about a HDD failure. I rebooted the maching and it started to "reformat" the HDD. Everything is gone now and it doesn't seem to want to let me change channels, its stuck on Channel 2. I had to leave for work, I will mess with it more when I get home. I am a little pissed off that there is no easy way to "backup" the 60+ hours of shows I was saving. How often does the HDD reformat itself? What is up with the system not changing channels?!