I'll guess that you have a lot of recordings set to "keep until I delete" When you use this, the Tivo assumes that it will never be deleted, so the space is not available for new recordings.thewolfe said:
or
You record everything at best quality (maybe high quality) which will turn your 80hr tivo into 20 hour tivo (or 40 at high)
or
you're using both KUID and recording at best or high quality.
and
If you have an 80GB (80 hour) Tivo you have an 80GB hard drive, not 60GB. You may want to correct that setting on tivoplaylist. Unless of course that was a typo in your post.