TiVo : Should I cancel tech visit

[Rewrew]

Our Tivo came up with the green screen warning about a serious problem and waiting 3 hours... After a bit of research on the Internet everyone seemed to indicate that this is a hard drive failure and unlikely to rectify itself. So I booked a tech visit for tomorrow after which predictably the Tivo came back to life with all recordings intact. So my question is, is the serious (undefined) problem really fixed? I will cancel the tech if the machine was just running some automatic defrag process or similar, but if it was remapping hard drive errors then I think it needs replacing. Is there any way to tell what the "serious error" was?

---------- Post added at 13:43 ---------- Previous post was at 12:54 ----------

To answer my own question my Tivo has green screened once more after 60 minutes. It seems the thing has died along with a 75% full 1gb hard drive

[spiderplant]

During the green screen, it is attempting to recover a corrupt database. As you've found, sometimes it is able to recover it, but if your hard drive is starting to fail you are on borrowed time.