EV9SP4 - export to pst and remove from archive

Hello all,

I have a strange issue on one of my environments.

I export a folder from an archive called: \inbox\training\.Personnel-Departments1\Closing to PST.

That works fine.

I then select the option to 'remove item from archive after export', I select the same folder again.

The export then fails, and shows error 6794 in eventlog:

Job Id: Exp3_20140108033500
Vault Name: USERNAME

Vault Id: 10DBC7E11939CE742BAF6038987A0F01A1110000AMRAFMAILARCHIVE
Saveset Id: 201310151875729~201307311608240000~Z~E148C91F2D4876803E22A3A19B3B4D81
Reference: RS/DI

I verified Vaultstore is not in backupmode, and retentioncategory allows deletions. I exported other folders succesfully, items have been removed.

Anyone has an idea what to do next?

Thanks,

Gertjan