I was wondering if bad clusters meant bad sectors. My friend her Tivo was freezing so I took the hard drive out and ran the Data Lifeguard software on the computer, and sure it enough the drive is failing. Thats the first time I ever seen a Western Digital drive fail with only 15,000 hours on the drive. As the software was running it kept saying "bad cluster bad cluster" and on and on and kept going that way. I thought maybe it might be fixing the drive and just had some file errors on it, but later on I booted the drive and got a message that said S.M.A.R.T. had tripped and back up the drive it was failing.