by ben reynolds.
Hmm. And you haven't recently upgraded? If yes, from which version?
I'm having trouble replicating this issue on my localhost, which is admittedly, 2.6+ but upgraded from 2.5.
If you upgraded from 2.2 or earlier, you will want to run the assignment upgrade helper, although I doubt this is the problem. You need Site Admin capability to run the assignment upgrade helper.