Service Reference Stops Working When Make Changes To WCF Service?

I'm using Visual Studio 2010 and .NET3.5. I've created a WCF service application. I'm including two DLLs that contain the types I'm returning. The first method I wrote works both in WCF Test Client and also in a console application I created to test. When I move on to the next method that returns a generic list of a type. It works great in WCF Test Client, but when I update the service reference it acts as if the service is unavailable. All my objects say can't find reference, and I can no longer see it in the object browser. It's like it just disappears. I can still see it in the Service Reference folder. If I go back to the WCF app and comment out the contract and implementation of that one method it work again. I created a local class very similar to the class I'm using from the dll, and the it works. Is there something I'm missing here? Can someone point me in the right direction?