'That's So Raven' Star Orlando Brown Busted for DUI

On a very special episode of "That's So Raven" ... Orlando Brown learns the hard way (allegedly) that drinking and driving don't mix.

Law enforcement sources tell TMZ ... Brown was busted late Friday night after officers pulled him over for driving without a license plate. We're told once cops went in for a closer look, they found that Brown smelled of alcohol -- so they administered a field sobriety test ... and he didn't perform well.