When setting up a bridge, do not display anything in the DirPort field
When setting up a bridge, Vidalia displays "9030" in the DirPort field. Even though it's greyed out, it does suggest to users that this port needs to be reachable. This is somewhat confusing. I think Vidalia should display an empty field instead.
If you set up a bridge you automatically mirror the relay directory. However, bridges do not open a dirport. Instead, they mirror via the orport.