If you try to add a role on a person using the role # instead of using the lookup you get an error at the bottom of the page when you click "add":
Not Authorized to assign role null null.
I'm sure this is because it's trying to figure out if I have permission to add the role I've selected but hasn't figured out the namespace yet. It would be great if we could figure out a way for it to find the namespace before doing this check.
At a minimum the error should be moved to the membership tab.