I already have all of my launch parameters removed and I am experiencing EXACTLY the same issues as Nick.

Things were going okay for appox 5 mins, then.. the lag kicked in and the buildings would no longer render.

I agree Bron. It's not a start perimeter issue. This has something to do with the most recent patch.

I've had launch options disabled for weeks... and the .54 patch just wrecked the rendering.

There is one particular male zombie.. that can't be trapped. Most other ones though.. you can still trap inside of closed doors. However... this one particular guy.. he's so OP that can just run through doors, no problemo.