Error while archiving folder "inbox" in store "mailbox - user name". Some items cannot be copied

Hi,
I get the following error message when Outlook 2007 tries to archive my inbox.

Error while archiving folder "inbox" in store "mailbox - user name". Some items canot be coped. They were either moved or deleted, or access was denied.

The archive inbox folder is now getting duplicated emails, and no emails are being removed from the normal inbox.

I have verified that the archive settings are pointing to the correct folder with full access rights, and the settings in general looks fine. It is a Microsoft Exchange email account, andI have the Use Cashed Exchange Mode selected, but as the archive file is correctly set up as a .pst file, I don't see why this could be an issue. (as per a similar thread in Experts Exchange).

I hope you can help me!