We seem to have had this for qute some time now.
Whenever manually sending/receiving in outlook we get an error which is seeming to be related to the OAB not syncing.
ALso some machines are not updating contacts in outlook that are on exchange.
Error in outlook is unknown error 0x80072f06
Deleting local OAB resolves the new exchange contacts and update on outlook clients.
However the error still persists and when clicking on the - send receive groups - download address book option (in outlook) i only see: download offline address book list, whereas in the past we would see: a drop down box including half a dozen address books.
Exchange 2010 sp1 still... But dont want to SP3 it until i know the problem is.
Could also have happened after we deployed Active Sync and OWA using SSL certs...