I am in the process of porting my game to Xbox Live with the assistance of an Xbox technician and my XDK console. Calling for the UserID, Achievement list, etc, works correctly. However, calling for the "update achievement" to unlock it (i.e., 100 percent) doesn't register.
For testing purposes, I created a loop that first call my achievement number "9" (i.e, the Achievement ID is located at number 9 in the Partner Center) and then if it fails, it calls for achievement "1" repeatedly every 10 seconds.
Strangely, via Fiddle trace monitoring, the technician told me that after obtaining the Achievement list, Xbox Live wasn't receiving the request for updating the achievement. However, it did trigger the "on achievement update error". No Xbox Live error message was shown.
I also tried using the name of the achievement (instead of the number), without success.
Has anyone been able to unlock their Xbox achievements? Any help would be greatly appreciated.