The --delete arg does not work

[Brian Vandruff]

I have two directories on the same systems that I want to keep synced
up. Only one is ever updated by my users. Rsync needs to update the
second directory. The problem is that when a file is deleted from the
first directory rsync does not delete it from the second directory. Why
not?
I run rsync from a command line at the moment. Here is the test comment
I did with two test directories:

     rsync -vau --delete ./dir1/* ./dir2

Can anyone help?
--Brian