Special Infected Problem

[Siraxisbryo]

When I play Left for Dead 2 I have a weird problem. I can see the regular zombies just fine but anything special like tanks, chargers, etc I literally cannot see the model until it is right next to me. They do not show up on my screen until they are right in front of me. As you could expect, this presents a bit of a problem. Any ideas what could be causing the problem or how to fix it?