what version are you playing?
from the sound of it... a reallllly really old version, like pre 1.05.
Have you registered your copy? If you have, you should be able to download patchs from impulse.
If you havent... find your serial number... then go here
hit the get impulse button, install it, make an account (assuming you dont already have one.) Once you got it up and running, go to "my games" and hit the "register product" button. fill out the little form, and you should see sins appear, with an update avalible button. click. done. play!