Lindsay Lohan is as predictable as a pineapple in a Mai Tai ... she showed up 40 minutes late for her "Scary Movie 5" premiere.

In fact ... she blew in 30 minutes before they rolled up the red carpet.

Her "SM5" and "Anger Management" co-star Charlie Sheen broke away from a few interviews to snap a few pics with the soon-to-be-in-rehab-but-not-until-after-she-goes-to-Coachella starlet.

Bet she won't be late when Phoenix takes the stage.