dl.dropbox.com/u/29072735/forcedscrollplat_test.cap
Here is an example of auto-scrolling. It's horizontal, but here's what you do.
Look in the Event Sheet "Camera", and see how the auto-scroll is set up.
Basically, you have a private variable "ScrollSpeed", and have the System scroll to Y + global(ScrollSpeed)*timedelta.
So basically switch where it says from ScrollX to ScrollY and it should work.