Etienne,
Have you seen this Behind the Blackboard KB article?
http://kb.blackboard.com/display/KB/ORA-01653+unable+to+extend+table
We don't run Oracle here, but that looked like it might be relevant to your problem.
Mike
Unfortunately if I click on the link it takes me to my Home page on Blackboard Support. I also can't find anything if I search for it in Behind the Blackboard.
Are you logged into Behind the Blackboard with a system administrator user account?
Yes
Try this direct URL:
http://kb.blackboard.com/x/zAB0
You may need to open a ticket if you're having trouble finding things in knowledgebase, though.