Like to other folks said, use dd_rescue or a cloning dock.Thanks for the input. Would spinrite actually work with the LINUX based TiVo hard drive? I went to the website and it appears its an MS-DOS based application.
The data on those sectors is likely gone even for spinrite, so trying to recover the data would be my last option.
The dd_rescue or cloning dock options will usually make some effort to re-read/copy the sector (sometime sectors have weak bits and re-reading over and over, you sometimes get a good read) and after a threshold will just insert a zero'd out sector on the copied version.
If the bad sector is in a recordiung, usually the zero'd out sector will cause a glitch but not a reboot, but even if it did cause a reboot, you could just delete the show and the area of disk would be overwritten by new recordings.
I've had good success recovering TiVo disks with bad sectors using dd_rescue, but it may not work for you depending on where your bad sector(s) are.