Error when trying to Export-Mailbox to .pst file (or import-mailbox) on Exchange Server 2007 SP1

When trying to export mailbox to .pst file in Exchange Server 2007 SP1 using Exchange Management Shell command "Export-Mailbox" I have encountered an error:
"Failed to copy messages to the destination mailbox store with error: MAPI or an unspecified service provider. ID no: 00000000-0000-00000000.."

To solve this run this command in Exchange Management Shell
"Get-Mailbox Add-MailboxPermission -User "" -AccessRights FullAccess"
and try exporting again.