here's an example of how the stop collision should be working for you just to confirm behaviour is as documented:
Graphics3D 800,600 Collisions 2,1,2,1 light=CreateLight() RotateEntity light,10,0,10 wall=CreateCube() EntityType wall,1 PositionEntity wall,0,-2,0 ball=CreateSphere() EntityType ball,2 cam=CreateCamera() PositionEntity cam,0,1,-10 While Not KeyHit(1) t#=10-MouseY()/20.0 PositionEntity ball,0,t,0 UpdateWorld RenderWorld Flip Wend End