I don’t know… there something wrong with colisions in 2.36… since 2.34 i dont have probles like the player going trough faces like it was in 2.25. But under 2.36, after moving fast (running) to one face for another the player goes to the black area. And yes i have set faces for collision. :x
The physics engine for Blender is currently implemented badly, if you want it better start coding!
it could be because the physics are no longer evaluated more than 60 [iirc] times per second in 2.36 that you are getting the same problem as if you had a low frame rate in older versions
you need to move slower, or use a larger bound on your object
though, there are a few bugs where objects will randomly fall through the ground, I think they are less of a problem than in 2.34
As always you are right z3r0 d !
It was just the size of the bound…!Thankx a lot.
I really think that something is strange because collision in 2.34 was much more stable in my tests. So i think to myself: what i am missing? And that was just the bouding area that is set to small. 
I USED to be a 14-year-old homeschool student. But in that time i also use some cordiality when i was on the street.