Had a problem last night when setting up a mailbox alias. I forgot to choose the target mailbox when creating the new alias and so ended with mail being sent to my default 'username' mailbox. I then used the 'edit' option on the alias page to set it to the correct one. Unfortunately the edit seemed to have no effect on where the email went. The pretty diagram on the 'alias' tab was displaying the alias pointing to the correct one, but all mail was still sent to the default mailbox.
I worked around this by deleting the broken alias and creating a new one - so haven't bothered to raise a ticket. Just thought somebody at PN may be interested.