I had some problems like this also.
Batterij terminals where corroded but seemed to be
working.
When I removed the batteries and used an adapter
(9V 1.5A) everything was fine.
Worth a try, isn't it?
On another one, a faulty cr2032 conversion on a
version 7 or 8 motherboard gave similar problems (not quite as extensive as your
problems though).
So, check the cr2032 battery (if present) or look
for a CR2032 conversion.