Okay, I've read a few things about the current OS version causing some problems, but this seems a bit different--I think. My Tivo is an S2 540040. I bought it April of last year and upgraded to a 250gb HD within the first month. My tivo started having problems back around August of this year. It seemed to be caused by overheating. It was slowing down and then rebooting about 2 times per day. (By "slowing down" I mean every time I press a button it takes about 30 seconds before it responds--if it does at all) I moved it to an area with better airflow and it seemed to be fine. Then after the new service update, it seemed to start again. But it started doing it more frequently. It was slowing down gradually and then rebooting. Then it got to the point where it was stuck booting up. I then put the original drive back in 2 days ago and it downloaded the service update. Then within a day it was already slowing down again. And this morning, it rebooted itself. Is this corruption of the data on the drive--both drives? Or could this be a bad power supply? Or is it the newest software version causing this? I have a backup of the drive from April of last year, when it was functioning just fine. I'll be trying that next but I wanted to get some opinions from the experts. One more thing, I've been keeping track of the temp and the highest I've seen it is 43C. It's usually between 38C and 42C.