Why does this game flog my CPU so?

When I look at the performance monitor it says that my CPU is constantly going at 100% (~92% Sins).  Now that doesn't make much sense.  I'm playing the smallest map (7 planets) and it is early on.  Now the requirements the game will work on:

P4 1.8GHZ or above and Recommended is P4 2.2 GHZ

Now I haven't checked the benchmarks but I'm guessing my Core Duo E 8400 that has 2 3GHZ cores should be more than enough to own this game?  What is going on and why does my game keep crashing.

The rest of my computer's specifications are:

4GB DD2 Ram, 8800 GT Graphics Card.