Hey,
I just thought of another thing:
These Contours are equipped with some sort of sensor in the key which works with the anti-theft system to prevent thefts from using a non-original key. Your system may not be correctly recognizing the key. If you have a spare, try using it to see if that makes a difference than your normal key. It may be a problem with the key or the car. You'll have to figure that out.
Your Ford Dealership can provide with a new programmed key if need be.
-Hal
