I just realized after glancing back at this thread, that our own dear dfowensby has decided to take it upon him/herself to make off-topic replies to old threads. Nice.
I see a gateway address already assigned to a system that appears to have a functional routing table.
Why are you trying to assign another gateway? Unless you're doing advanced routing, there should be no need to do so. The way you have your system configured now, when network activity that cannot be satisfied with the various routes you have assigned, that request is then forwarded to the default gateway.
It appears your system isn't working properly. What is the problem?
If I were to guess, I would think that IP forwarding isn't configured. Check out this site and see if you have it enabled:
If that is configured correctly, let us know what the issue is.