TGB Screen Resolution?

I have TGB installed with default settings. The Screen Resolution is set to 800x600. I set the resolution to 2048x1152, but after adding sprites at that resolution they seem to stretch. To demonstrate, I am using the first Behavior demo and I am adding Tank Controls to a sprite. As it moves around the screen and rotates, it stretches. How do I keep everything proportional. Under Camera Settings, there is a width and height setting. If that's what I have to set, where can I look up what the correct ratio to my resolution is? Is there a table? There has to be an automatic setting somewhere. Anyone? In case you are wondering, my interest is to have a top down view, so I don't want any distortions.