no version 6.5 has the new collision or at least thats what the main page says in the versions sections.
And the problem sure isn't about the scale. I have a my game posted in the user requests, it's posted as "Game" if you download it and take a look i would apreciate alot.
I'm sure i'm having the same problem modeldeveloper is having.
Modeldeveloper could you please dowload it too and check it.
I have the problem with the stair almost solved. I forgot to add mod_stairs action to it

Now the rest of it is breaking my brain apart :S
I added a mace to the floor tryed every type of collision with it and it just stucks in there...
