Windows CE - Strange crash

Hi !

I'm currently developing a litte tool for Windows CE.
It's a Form-bases Application and the GUI is made up
mostly of Editboxes, Checkboxes and Optionbuttons.

The problem now is that the program hangs when
a Checkbox has the inputfocus and a 'normal' key
( like a,b,c,1,2,3 ) is pressed.

I just can't seem to figure out why this is happening
so if anyone out there has a clou, please let me know.

System: Casio Cassiopeia (Palmheld, MIPS R4000)

Windows CE Version: 2.11

SDK-Version used: 1.2

regards,

Matthias.