Application Data Folder Redirected:
If your Application Data folder under Documents & Settings folder is redirected to an external source, you will experience synchronization failures.
Please upgrade to ActiveSync 4.1 if you are experiencing this issue.
Outlook is in Offline Mode:
If you are attempting to set up synchronization or are synchronizing when Microsoft Outlook is in Offline mode or when you do not have connectivity to the Microsoft Exchange Server with Outlook, you may experience synchronization failures.
Please upgrade to ActiveSync 4.1 if you are experiencing these issues.
It is still recommended that you have Microsoft Outlook in the Online mode when synchronizing with your device.
Outlook Scripting Blocked:
Certain Desktop PC security applications may disable Outlook scripting which is required for ActiveSync too set up communications with Outlook to synchronize data.
Please ensure that script blocking for Outlook is not enabled to work around this issue. Please consult your PC security application documentation on how to disable script blocking for Microsoft Outlook.
Incorrect Outlook Registration:
Please see “Outlook needs to be Re-Installed or Repaired” section for details.