Who owns teaching materials?

Only a week ago I ran into an interesting question which arose for the first time. A member of the teaching staff had left university and removed course materials from his/her Blackboard course. Staff preparing the course site could not find the materials which were in place last year.
We have not got our Learning Objects repository in place yet, otherwise this would have been the perfect place to recover these documents. It does clearly show that a discussion on the intellectual property rights of teaching materials created by teachers is worth while. Actually: the discussion itself is not all the interesting, if a teacher has created materials while being employed by the university, the copyrights belong to the university. I practice however not everybody feels the same way about this and that is why it would be a good idea to raise this discussion.