Hi guys
Not sure if this will be helpful to anyone but I have found that using the cybook outside of its cover does not trigger the page-not-turning-even-though-the-LED-turned-green problem as much (when using my right thumb). I switched hands while drinking a cup of coffee and it got the problem almost immediately after 300 - 400 perfect page turns. It might have been a coincidence but I don't think so. It is possible that this is sepcific to my unit.
Still on firmware version 538; decided to wait for the next update since there seems to be such a mixed bag of opinions.
I'm going on my first holiday since getting the cybook. Really looking forward to the cybook experience while waiting in the airport & being stuck in a plane seat for eight hours