Hi,
The two most common causes for this issue are as follows:
1. You are running an old version of Desktop Manager. Go to
www.blackberry.com/support and from Downloads select the latest version (e.g. current version 4.5)
2. You device has one or more corrupt databases. To resolve this perform and backup and then restore using Desktop Manager. If you are on BIS logon to the web client and resend the service books once complete, or if you are on BES you will have to reactivate.
Let us know how you go.
Thanks,
Gary