I was playing a co-op game where we had to take out a building that was an enemy HQ, so a couple guys put some m203's into it and one of the sides collapsed; making it almost impossible to enter. I was watching one of the sides and all of the sudden my guy started "floating" on invisible debris; not to mention the guys who went in to clear it kept getting stuck on invisible barriers.
Maybe having partial-destruction for buildings with this old engine wasn't such a good idea