Rio 600 battery drain issue?

Dan Mangialetto found that the batteries in his new Rio 600 were completely drained within a week, even if the Rio was off for the entire time. He contacted Diamond tech support about this and they sort of confirmed this as a potential problem, replying: When the Rio is not in use, remove the battery. The Rio has saved settings that use the battery while not in use. Update: Bob Eller replies: "We have 2 Rio 600s. I've never had a problem with drained batteries from sitting. I've had mine in my bag for about 2 weeks without use, just checked and the battery is at 82%. Yes, it does use the battery to maintain settings but complete drain in a week seems a bit excessive. Perhaps the user thought he had turned the Rio 600 off when he actually clicked into the center "hold" setting. That would force the Rio to stay on until the battery expired." Another reader adds: "The batteries drain much faster when the backlit display is activated. Disabling this results in about 11 hours of playtime instead of about 2.5 with the display backlit." Update: Dan Mangialetto replies: "I can definitely confirm that my Rio 600 was turned off and not in the hold position. It may be that the switch is defective and is not truly going to the off position but I do not know at this point. My Rio completely drained this new battery in just 5 days. The good people at Diamond are going to replace the unit."