this happened me a couple times, most likely culprit seemed to be corrupted memory (running out of battery while hibernating. also, crashing+freezing kindle app and google books app)
didn't have the time to track anything down, so I simply reflashed golden allmine each time (probably not the answer you wanted). after the second (or third?) round of that, it had finally occured to me what was likely happening. since then I've avoided the abovementioned causes and have not had the problem again.