I'm sure there is a simple explanation for this. If in the scene shown about 30 secs into the video, (just after unchecking 'soft body goal') you make the plane a collision object, the sphere sort of splats in on itself and no longer goes through the plane. I think that's as it should be. Then if you uncheck the collision parameter for the plane, exactly the same thing happens! This is even though in the exact same scene the sphere passed through the plane before it was given collision status. That's weird enough, but if you actually delete the plane, the sphere splats in the area where the plane was. What's happening?
Hey Jim, that sounds like a cache not refreshing. Blender stores the simulation data for faster playback in the future, but there are a few properties that don't clear the cache when changed. I guess the collision parameter must be one of them. If you need it to update, try either changing the mass a bit and then changing it back, or saving and reverting the file. Hope that helps!