After mailbox move users cannot open premium version of OWA

Hi all,

Strange one here.

I have a perfectly working installation of Exchange 2007 in one domain of our forest.

I was asked to create a new domain in a new tree and migrate everyone across to the new domain.

In the new domain I installed 2 HT/CAS servers and a clustered mailbox server.

Now users that I have migrated to the new domain can open the LITE version of OWA but not the PREMIUM version.

I checked that the Forms based authentication settings are the same from the old HT/CAS and the new ones but can´t think why the OWA won´t fully work.

If a user tries to acces the premium version they get the "Outlook Web Access could not connect to Microsoft Exchange".
Also listed under the details of this error message is:

Exception
Exception type: Microsoft.Exchange.Data.Storage.ConnectionFailedTransientException
Exception message: Event Manager was not created.

Inner Exception
Exception type: Microsoft.Mapi.MapiExceptionNetworkError
Exception message: MapiExceptionNetworkError: Unable to make admin interface connection to server. (hr=0x80040115, ec=-2147221227) Diagnostic context: ...... Lid: 13720 dwParam: 0x6BA Msg: EEInfo: Flags: 0 Lid: 11672 dwParam: 0x6BA Msg: EEInfo: NumberOfParameters: 0 Lid: 16280 dwParam: 0x6BA Msg: EEInfo: ComputerName: n/a Lid: 8600 dwParam: 0x6BA Msg: EEInfo: ProcessID: 5092 Lid: 12696 dwParam: 0x6BA Msg: EEInfo: Generation Time: 2008-11-07 04:58:31:876 Lid: 10648 dwParam: 0x6BA Msg: EEInfo: Generating component: 8 Lid: 14744 dwParam: 0x6BA Msg: EEInfo: Status: 11001 Lid: 9624 dwParam: 0x6BA Msg: EEInfo: Detection location: 320 Lid: 13720 dwParam: 0x6BA Msg: EEInfo: Flags: 0 Lid: 11672 dwParam: 0x6BA Msg: EEInfo: NumberOfParameters: 1 Lid: 8856 dwParam: 0x6BA Msg: EEInfo: prm[0]: Unicode string: ONEXC01 Lid: 24060 StoreEc: 0x80040115 Lid: 23746 Lid: 31938 StoreEc: 0x80040115 Lid: 19650 Lid: 27842 StoreEc: 0x80040115 Lid: 20866 Lid: 29058 StoreEc: 0x80040115

Can anyone suggest anything in particular that I could check or should be looking at?

Thanks