I forgot to remove my personal debug setting from the GameAPI demo before releasing it.
Start EVC. Open the GameAPI project. Enter "Project", "Settings".
Switch to the "DEBUG" tab, and change category to "Additional DLLs". Mark "gapitools.dll" and press Delete (the red cross).
If you now recompile the project, it will ask you for your presonal location of the DLL.
The next release of GapiTools due this weekend will have native Windows 2000/XP support. So you can use a better environment like Visual Studio 6.0 or .NET to create your games, and then just recompile for the Pocket PC later.