How many movies have Christopher R. Sumpton and Melissa R. Stubbs collaborated on?

They have worked on 2 movies together! Their first movie together was Disturbing Behavior (1998) while their highest rated movie together was Scooby-Doo 2: Monsters Unleashed (2004). They have not worked together since Scooby-Doo 2: Monsters Unleashed (2004).