Am I missing a right?

Using RT 4.0.4

If a ticket is owned already, I cannot re-assign it unless
I set the owner to Nobody, then assign it.

Is this normal behavior?

Hey Jeff
You are not allowed to Take a ticket that is owned by someone, you have to steal it, which is in the Actions tab and is a different right.
Chris

Using RT 4.0.4

If a ticket is owned already, I cannot re-assign it unless
I set the owner to Nobody, then assign it.

Is this normal behavior?

Yes. To assign a ticket you someone, the ticket either needs to be
unowned or owned by you. So you could also Take the ticket (making
yourself the Owner) and then give it to someone.

RT uses Owner as the only form of ticket locking.

Thomas