iSync is no longer included with Lion OS

Since iSync is no longer included with Lion then this will get tricky. See if this solution from another post works for you:

You can try to delete the preference files. After you do this, you will need to reactivate Sync Services in the Outlook Preferences pane.

1. Quit all applications.
2. On the Go menu, click Home.
3. Click Library folder, click Preferences folder, and then drag the following files to the Trash:

com.microsoft.Outlook.SyncServicesPreferences.plist

com.microsoft.Outlook.SyncServices.plist (if it exists)

OfficeSync Prefs (if it exists)

4. Click Microsoft folder, click Office 2011 folder, and then drag OfficeSync Prefs to the Trash.
5. On the Apple menu, click Restart .
6. Open Outlook for Mac.
7. On the Outlook menu, click Preferences, and then Sync Services.
8. In the left pane, check the boxes next to the items that you want to sync, and then close the dialog box.