I was having problems with the keypad on several older programmable scanners
(Pro 43 & 26) and found this great fix called Lub-a-Spray made by Panef for
$1.75 at the local hardware store. All I did was remove the case, remove
the rubber keypad, lay it on a paper plate with the underside face up and
squirt this dry graphite lube into all the open spots with the applicator,
shake the loose material off, place back in the scanner and it works like
new. Be very careful with this stuff, as it's quite messy, but it works
great.