I have been losing the guide on my Pioneer 531 about every 9 days since I first found about about the "number reset". That's been about 6 months now. If I use the machine every day then it is exactly at 3:30AM on the 9th day that it disappears. But about every 6 weeks I go away and don't use it for up to 8 days. If I reset it just before I leave I then get up to 17 days between crashes. If I left after say 5 days then I might get 14 days. So I knew it had something to do with letting it rest or not letting it rest and it seemed to take 9 days from the time I started using it but if there was a several day rest before it was supposed to crash it "repaired" itself.
Another bug I had found was that it could lock up the entire machine if I edited too fast. (Once you learn the keys you can clip 3 minutes of commercials suprisingly fast.) It would also put holes in a recording if I was editing one program while it was recording another. Again, this occurred only if I was going too fast. If I would wait for the preview to start playing or the pause indicator to show before pressing another function, then no lockups and no holes. So what does this have to do with losing the EPG...
Well, I just went in to see if it was ready to record this evening and found that I had forgotten how much I had scheduled to record yesterday and today. It was sitting there with EPG off and when I turned it on it said the HD was full. Oops. Ok, no big deal. I lost the last part of the last thing I recorded. But wait! The EPG has no data! It was supposed to last until 1/4/07. And it isn't as simple as running out of space corrupted the EPG. I ran out once before a couple of months ago and no problem. I was away at the time and had scheduled more than I thought while I was gone. But when I came back it just said it was full, I erased some (moved to DVD) and the EPG continued to work normally.
Speculation: Could it be that the EPG tried to update and finding it had no HD space, corrupted the end. Now it won't work. But if left to itself it starts erasing it's own data for yesterday making room for new data and, knowing it is short on space, makes sure it has enough room before adding new data? Just and idea but I can see both the loss of recording data during editing of another program, Aydu's 28 recording limit, and a sudden corruption when the HD is full all being related. The TVGOS is running in the background so as not to interfere with the user events or recordings but it was written as if it was the only thing running on the machine and it needs HD access immediately when it asks for it. If the HD is busy doing something else when the EPG gets and update, the listing is corrupted and at some point the entire listing is corrupted when it tries to erase a bad listing and insert a new one? Therefore, if I edit slowly, keep the automatic scheduling to a minimum, don't start and stop too many recordings in a day, and maybe give it a couple of days rest every week, will the EPG keep running? That's the next thing I'm going to try.