Ticket 28: Permission Denied

On a new RT installation, when updating a ticket (#28 to be specific), I
get this:

Results

 * Message recorded
 * Ticket 28: Permission Denied

The updates I made were allowed to occur, but the Permission Denied
error popped up. Any idea why? This user has full rights to update the
ticket. How can I see more specifically what I tried to do and then was
unable to do?

I played around a bit this morning and can explain this problem in more
detail.

I have a ticket where my user can not change its status. If i try to
change the status, I get a permission denied error. I can change
anything else with the ticket, but not its status.

I can also change the status on other tickets in the same queue.

I am worried this might be database corruption. Any suggestions on what
I can look at?