When activations get stuck around a particular percentage, it is commonly caused by a corrupted entry in the user's files.  Potentially a blank Memo or Tasks or contact with a blank first and last name.  Try deleting these types of entries and try the activation again.  

A work around is to disable wireless PIM synchronization. 

To enable or disable wireless PIM synchronization, please follow the steps below:

1. On the Home screen, click Address Book
2. Click the trackwheel to open the calendar application. Press the Task key, and select Options.
3. Using the trackwheel, Select the desired Address Book.
4. In the Wireless Synchronization field, press the Space key until the field displays:
   • Yes (to enable wireless PIM synchronization)
   • No (to disable wireless PIM synchronization)
5. Click the trackwheel and select Save
6. Click the trackwheel and select Close
7. Press the Escape button
8. Repeat these steps for Calendar, MemoPad, and Tasks