Moblie Development Based on. NET Compact framework3 question: ActiveX

On How to hosting ActiveX controls in the. NET Compact Framework 2.0, MS did not give a answer. There are 2 solutions cfcom and opennetcf, which I have mentationed at the above post.
I have worked for two days to host hosting a GIS ActiveX: Mapx Mobile in CF.
At last, I can make Mapx Mobile A. Net CF control, it can display at the toolbox, and I can drag it to my mobile form.
It complies well.
But when I run it, I get a exception:
"Not registered"
Hresults =-2147221164
The exception occurs at the ActiveX instance method.
Did anyone come into SS such problem?
If u know, pls leave some info about the solution.