Boy, that's bizarre. If these forums are any indication, the flashing screen/reloading arrows doesn't seem to be a frequent or common occurrence. And in truth, I've only had it happen once so far. I'm hoping it's just a fluke or due to a funky epub. But who knows?!
Helen, have you tried a hard reset?
http://www.kb.sony.com/selfservice/d...nalId=C1024494