When I first purchased this game for my PS3, 90% of the game was broken. Enemies and walls were invisible, no one talked during cut scenes, my gun made no sound, and the enemies didn't respond or move when I was shooting at them. I went back to Gamestop and exchanged it for a new copy, and when I got back to my PS3 I deleted any and all data from the previous game. With this disc I only sometimes have problems with inivislbe walls, broken cut scenes and floating enemies, but there are also some other problems. The menu is very laggy and slow, I temporarily freeze a lot in and out of gameplay, and during gameplay I cannot use the XMB after hitting the PS3 button. Is there a way to fix this?

Here is what I am currently experiencing and unable to get to the next checkpoint: http://www.youtube.com/watch?v=YIXFhBXeAIw