Orlando Brown Caught in the Act Before Burglary Arrest

Orlando Brown reeeeeally likes to smile for the camera -- problem is, lately he's smiling for mug shots ... the most recent one coming Sunday morning for the ex-Disney star.

Law enforcement sources tell TMZ ... Orlando was busted in Vegas after he was caught on camera changing the locks inside Legends Restaurant & Venue. You can see him wandering around the kitchen and eventually using a rag to cover the security camera.

The restaurant is owned by ex-Death Row artist Danny Boy, who's been friends with Orlando since they were kids. We're told Orlando's presence triggered a security alarm and alert on Danny's phone. He called the cops ... who say they found Orlando on the roof, claiming he was there with permission to change the locks. Danny shot that down ... and Orlando was arrested.

Danny tells us Orlando was released from a hospital 2 weeks ago and needed a place to sleep, so he invited him to stay in the restaurant. He says Orlando appeared to be in a haze Sunday, and accused Danny of stealing money from him.

Danny says pressing charges seemed like the best way for Orlando to get the help he needs.

This new arrest complicate matters for Orlando, whose bond in 2 previous cases has been revoked. Orlando remains behind bars and bail's set at $13k.

TMZ broke the story ... Orlando posed for an incredible mug shot after some family beef. He was arrested just last June for narcotics possession when he showed off a new tat in that mug shot.