I have a Series 3 Tivo (w/ lifetime) that has been running great for the most part. Occasional lockups occurred, but a total power down (pulling the plug) has always helped solved it. Well, today I was transferring a video file over my home network (totally wired) with PyTivo and it stopped in the middle of the transferred and locked up the unit. I unplugged it, waited a few seconds and plugged it back in, but it got hung up on the welcome screen for over 20mins. Unplugged it again, waited and plugged back in. Hung up yet again on the welcome screen. Decided to unplug it and let it sit for a while. Came back about 2hrs later and plugged it back in. This time it appeared to boot up normally & it got back into all the channels. I thought all was good, but about 15mins into watching an HD channel, I started getting occasional audio & video breakup a bit. Changed it to a SD channel and wasn't having any issues. Haven't tried transferring another video with PyTivo yet either. I'm not sure if there is anything to really worry about here & maybe I am overeacting, but bottom line is I'm wondering if the hard drive might be failing. If so, I decided I need to maybe look into and learn as much as I can about installing a new hard drive in this S3 if needed. I feel pretty comfortable about doing it myself since I have custom built desktop PCs on my own and installed hard drives in computers MANY times. From what I have learned so far from here, I can basically use WinMFS (http://www.mfslive.org/winmfs/) and then have to have a TiVo ISO image of some kind. Is this correct? Or is there an easier way? Or can someone maybe point me to a better place that will lay out how to change/upgrade a TiVo drive? Also, what are some better brand of hard drives for putting in this Series 3? Seagate, WD, Hitachi, etc?