First, have you tried replacing your batteries, doing a hard reset,
then attempting to recalibrate. Batttery strength impacts the digitizer
readings.
Next, do you have a backup of your Zoomer's GEOS.INI? Do you have a buddy
with a Zoomer and can you get your hands on his/her GEOS.INI?
What you want to do is get more appropriate calibration information into
your Zoomer's GEOS.INI. I've previously published a PCMCIA RAM card
procedure to get control of the Zoomer before GEOS loads. You can use
that procedure to transfer a replacement GEOS.INI into your Zoomer.
On the other hand, no matter what you put in your GEOS.INI, it won't help
if you actually have a hardware failure of the screen's touch sensors.
Regards,
Garland