JBlyth - Several people on the Kobo forum have suggested this problem often occurs when side loading from different applications without ejecting the Kobo first. As in, I download or sync with the Kobo desktop software then I open ADE without ejecting the Kobo first and download from there as well, or simply open ADE for whatever reason.
I know this was something I did on an occasional basis and I have had four factory resets over five or six weeks. It's too early to tell, but since I made the change (always ejecting first) I have reloaded 250 books or so from calibre and I have not had the problem repeat itself since.
Also, several people in different threads related to this problem, stated they did not use calibre and were experiencing the same problem.
Last edited by fbrII; 08-03-2011 at 06:52 AM.