Is it PocketPC 2000 or PocketPC 2002?
PocketPC 2000 and PocketPC 2002 are significantly different, and software designed for 2002 will probably not work on 2000.
Unfortunately, it is really quite difficult to determine which version is installed on a given PocketPC. Here is how Microsoft says you should tell the difference:
I kid you not. That's how you're supposed to tell. How do those guys manage to get all the money?