Dead Space - Chapter 9 Dead On Arrival *POSSIBLE SPOILER*

I don't know if this is supposed to be part of the level, but on chapter 9 in dead space, when you enter the USG Valor, everything is sliding towards the back end of the ship. (Most likely the part extruding from the Ishimura). My question or problem rather, is that everything in the level is slowly sliding towards the back, which may just be happening because of some eird vaccume action. The things sliding back include the random things strewn about the desks, the bodies and limbs of dead people, and the giant crates that I'm only supposed to be able to move with kinesis. That part is the major one because these giant crates dissappeared through the wall after moving THROUGH other crates that were in between where they started and the back wall. Any ideas? Its also making everything really laggy throughout.