Glad someone can benefit from it. I had the first R1 from my retailer and botched 3 shows due to this unknown requirement. I never got any response from anyone at Edirol but luckily someone here knew that was the culprit.
If you had to re-format before every show, did that mean you had the probability of botching a recording if you recorded two bands on the same card. Such as an opening band and then a headliner.
dB-
The way I believe it worked was - the first show I taped a 45 minute opener and then a 90 min main set and 30 min encore (Rose Hill Drive/Black Crowes). Went home copied files off, deleted files, but didn't format the card. The next show, I didn't exceed the total time of the previous show (165 min), so I didn't have a problem with a recording stopping. But the show after that after not formating again, I taped a 2 hr main set, stopped and started the 2nd file and the R1 just stopped recording at the 45 min mark which happened to be around the 165 min mark that coincided with the total time of the 1st show. After multiple attempts to restart the recording, the R1 would just stop again after writing out a few seconds.
So I think by deleting the files and not doing the format, I was restricting the total time/space on the card to the total time/space used by the original set of files that I deleted.