Thanks for the congratulations
, but it's more of a workaround than a fix, and I'm not sure if it was just randomly triggered on my unit or if it's effectively widespread. Google searches report several people complaining about this, but definitely not enough to make it stand out like a very common bug. I haven't tried to reactivate it to see if it happens again, so your mileage may vary.
I decided to try those steps because the latest Opus firmware had a similar bug about the "reverse side buttons" option, which lets you use the bottom key to go to the next page and top key to go to the previous page (just like the Kindle), whereas the default is to use the top for next and the bottom for previous. The problem was that enabling that option only worked as long as the unit didn't go into sleep mode. When waking it up, the buttons worked in their default position even if the "invert buttons" option was set to on. To re-enable it one has to disable it and re-enable it. Incredibly frustrating, especially considering that Bookeen is well aware of the problem but refuses to release a firmware update that would only really only require to change no more than a few lines of code.