The patch today fixed some of my video issues, but now, I also have some issues with invisible enemies. Plus, my sound will still occasionally cut out.

Yeah i'm getting both the invisible enemies and the loss of sound as well now, seem to happen at random to, annoying as hell.

The game has issues with loading graphical information, and then deleting it so that you have to reload it again. This is causing a lot of the current FPS lag.

You'll notice this happens when running into a new room, and it's choppy for a bit, and then goes smooth.