Advertisements Hard drives can fail for a number of reasons. Bad sectors can cause problems and not be immediately apparent. If a hard drive has bad sectors the instance when a problem would appear would be when TiVo tries to write to those sectors. Bad sectors can be the result of manufacturing defects as well as subsequent damage to the platter(s). Error correction can overcome some issues, but may not be able to handle larger ones. Theoretically a drive could perform fine for quite a while depending on where the bad sectors are located. If the bad sectors are located in the root partitions used to store the software files an upgrade could highlight the issue. Read/write heads can be problematic as well; allowing a drive to function normally for months or years and then presenting with errors as well. Whatever the case hard drive issues are not always apparent or the same for everyone and of course not all cures work for everyone everytime.