Physics difference between engine releases

Uhm, is it just my imagination or is the A7 physics reacting differently every engine release? Sometimes i can push the box and it tumbles, where in other release it glides like it was on ice. Also when I let the boxes fall in on eachother and they have come to rest on the floor (wed block), they show spastic movement now and then. Unless i'd set their mass to 0 that is.

I'm working on vehicle physics, and seems it works great (from A7 up to A7.07).
However, I will do more checks :-)