Exchange Address Book sync problem

Dear all,

After some tweaking I've managed to get our companies' Exchange server work fine with my Mac for iCal and Mail. However, for some reason, my Address Book doesn't sync or show the address list from our Exchange server, even though the settings for Mail and iCal are identical to the ones I put into the Address Book settings.

Any idea's what could cause this?

Thanks in advance and best regards,
Tim Metz