I use a Sony Clie' Palm OS organizer. My new-to-me refurbished unit did not always respond to my input from the stylus as expected. I learned with some web searches this is called the "Mad Digitizer' syndrome.
Step 1: The Way It Is Supposed to Work
You are supposed to tap on the screen with the stylus and the input registers where you tap, assuming you have regularly used the Welcome Screen to calibrate inputs from the stylus on the screen.
My problem was that stylus inputs often did not register, or the stylus had to be quite far above the target area to get the desired input. So, to change the display from Monday's daily calendar (shown here) to Wednesday's, the stylus would need to be almost off of the frame of the screen, and then it likely would not work. I would need to use the up/down scroll button to advance to a new day of the week. Fortunately, there is an additional option for making the screen respond as desired. Often I would end up on the wrong day or the wrong menu option.
Step 2: Digifix to the Rescue
Digifix is a small freeware program that fixes "Mad Digitizer" syndrome. It comes in a zipped file and unzips easily. There is some documentation on its installation and use. You can read the URL in the screen shot, but it is: http://www.freewarepalm.com/utilities/digifix.shtml
Download it. Unzip it. Install the necessary files. One file, Digifix Hack, is not needed if your Palm OS is 3.5 or higher.
Digifix has been around since 2003. I have no connection with its developers in any way.
Step 3: Finding Digifix on Your Palm
Digifix will appear on your menu window in whatever category you choose to list it (Untitled, Main, etc.) Open it as you would any other program.
Step 4: Using Digifix
When you open Digifix follow the prompts. It looks and acts very much like the standard calibration software in the Palm OS. Digifix is not supposed to work on Sony Clie' handhelds, but it solved my problems. I can now navigate on my handheld very easily, whether I use the factory stylus or the corner of my fingernail. It is almost like having a new handheld.