Sorry for the long delay, I've missed your response due to holliday's.
I did indeed have a client task running and (because I couldn't find a disable option) deleted it. The import task for AD accounts has been changed for now so i hope it doesn't import any pc's anymore.
Apperently I've not been clear enough on cloning: we don't do cloning anymore. Every PC is reinstalled with MDT from the original MS ISO.
The next question is: how to get rid of all the duplicate entries in our database?