My poly 800 is having some weird problems. Some of the keys give no response and others seem to play 2 notes. I'm also having trouble with the number pad. If I try to key in a sound in the teens, it automatically selects 15. There are also other problems like this. I reloaded the factory patch, and that didn't seem to help. Any thoughts on this? I'm going to drop the batteries and open it up.

-Brian