Secret, which OS do you have wm5 or wm2003se? If you have wm2003se then you're using the wrong version of Active Sync. You need 3.8.
This should be the solution. If not, you have to do a search to find it. You cannot just delete 4.x, you have to go thru a whole process, otherwise you're wasting your time.
If you have more questions please post them.