Ryan,
The IC pump failing is a know problem with this engine. Just spend some time reading the boards at MBworld and you'll see that they talk about replacing the pump once the car has 40-60k miles on it. Since you're still under warranty, just take it to the dealer and have them check it out. If you're out of warranty then I'd look at replacing the pump with the Ford Lightning IC pump. It's definitely the first place that I'd look to fixing your problem.
Let us know what you find.

John