Switching a mailbox fails with: CSession::Logon| Number: -2147467259 - Unspecified error (4344670)

When trying to switch a mailbox manually it fails. EMWMigration.log doesn’t provide any information, and even with extended logging enabled for MBREDIR the information is scarce and the error just says:

10/11/2011 4:00:50 PM MMExCore|Quest.MigrationManager.Exchange.Informer.informer_WriteLogInfo Message: Severity: 5| Source: CaeMAPISession::Logon| Number: 0 - Trying to synchronize MAPI profile creation. |External source: aeEMWGUIForms.CMBRedir.Log event
10/11/2011 4:00:50 PM MMExCore|Quest.MigrationManager.Exchange.Informer.informer_WriteLogError Error: 0 - (Source: CSession::Logon| Number: -2147467259 - Unspecified error File: 'aeMAPIProfile.cpp' Line: '130' | Source: aeEMWGUIForms.CMBRedir.Log event)
10/11/2011 4:00:50 PM MMExCore|Quest.MigrationManager.Exchange.Informer.informer_WriteLogInfo Message: Error: Cannot switch mailbox '/o=Correo Cerveza/ou=OC Administrative Group/cn=Recipients/cn=DummySINC18'. Result: -2147467259. Last error: 0. |External source: aeEMWGUIForms.CMBRedir.Switch
10/11/2011 4:00:50 PM MMExCore|Quest.MigrationManager.Exchange.Informer.informer_WriteLogInfo Message: One or several mailboxes were not switched due to errors. See the log file for details. |External source: EMWCon.CModMisc.MsgBoxEx