Originally Posted by matthias
Maybe the Kobo didn't like me to delete the book it wanted to show the cover from - however a factory Reset should have resolved this, but it didn't...
so eighter it's still saved somewhere and the kobo can't overwrite this setting - or there is a bug in the firmware not allowing more than a few books loaded from calibre...
i'd really apreciate an idea about this...
I'm running over 1500 sideloaded books so I don't think it is a limit on sideloaded books.
I'd suggest a factory reset, let the Kobo run through it's entire sync and update procedure, then add 2 or 3 books and see what the results are. If they look good, my suspicion is that you have a corrupted book which is causing your problem.
If those first books look good, I'd add a few books at a time and allow the Kobo to process them after each addition to see if you can isolate the corrupted book.