My tivo has been freezing up, I connected a serial cable to see what's going on. These are the messages:

hda: drive not ready for command
hda: status error: status=0x00 { }
hda: drive not ready for command
hda: status error: status=0x00 { }
hda: drive not ready for command
hda: status error: status=0x00 { }
hda: DMA disabled
hda: set_drive_speed_status: status=0x00 { }
hda: re-enabled DMA
hda: drive not ready for command
ide0: reset: master: error (0x00?)
hda: status error: status=0x00 { }
hda: drive not ready for command
hda: status error: status=0x00 { }
hda: drive not ready for command
hda: status error: status=0x00 { }
hda: drive not ready for command
hda: status error: status=0x00 { }
hda: DMA disabled
hda: set_drive_speed_status: status=0x00 { }
hda: re-enabled DMA
hda: drive not ready for command
ide0: reset: success
hda: lost interrupt