As just about every PDA owner will attest to, there comes a time in a PDA's life where digitizer drift sets in: the PDA registers a screen touch in a different location than where it actually occurred. My first Handspring Visor suffered from this before eventually dying. My Tungsten T3 currently has a mild case of this.
Palm PDAs have a built in digitizer program that's supposed to help recalibrate the digitizer. Most of the time it works...for a while. Sometimes it doesn't help things at all, or ends up making things worse.
There are a few programs out there to help stricken PDAs. DigiE was one that I used before that helped a little, although the middle of the screen would still be off. One problem with DigiE I had was that it kept turning the PDA on (software bug), so you either have to move it to the SD card, or uninstall it after calibrating.
Then I stumbled onto a new program called PowerDigi. It's pretty slick, offering 3 different levels of digitizer recalibration utilizing different numbers of screen taps. Works beautifully and cured my T3 of digitizer drift (for now at least). One thing I have noticed is that Grafitti recognition is kind of slow when using the DIA. Otherwise I can tap all over the screen and not worry about guessing where I need to tap.
Severe digitizer problems? Try PowerDigi. 14 day trial mode, and it's pretty cheap.
5 stars out of 5.