Originally Posted by Seqkat
It turns out that somehow, it's loading more than one book at a time which causes issues. Also if any of these steps is skipped, it doesn't work. I realise that this sounds vaguely ridiculous - is it likely that this is just because it's a very old and now slightly mercurial e-reader? Or is this a problem that anyone recognises?
The reason may be that the firmware 1.0 didn't have folder mode, only library mode which means that it has to include all the new books into the internal database and doing it with more than one book "overcharges" the device. But anyway - you've found a solution - great!