I did the factory reset and that seems to have done the trick for now. Everything went back to behaving normally so I can only assume the programming got 'confused' somehow. It is the 1.09 eprom (the latest?) if that may make any difference. I also took out the battery and cleaned the contacts to see if that helps my shortened battery life any. Only time will tell. At least my unit is back to it's old self again!
Great! and v1.09 is in fact the latest EPROM.
Should the problem resurface, perhaps the hardware is failing and replacement is in order. I would not entertain paying for repair or servicing as most factory service centers repair nothing, but instead, usually just swap yours with a refurbished one. I'm sure service charges would be $100+ and a typical sale price on a brand new unit is $149.
Good luck!