That setting was indeed set to Windows Address book. I've changed this now and set it to Outlook, but still any changes made to my contacts on my iPad is NOT sync back to Outlook
Could it have something to do with the MobileMe synchronisation?
I've installed MobileMe to sync my web bookmarks, the syncing of contacts doesn't work as Outlook is connected to an exchange server and MobileMe doesn't work with Outlook/Exchange server. Only with stand alone Outlook client.
Any other suggestions?