wpf app - why is the window size larger than I set it to?

Any ideas re why the WPF application I've starting building has a larger width and height than what I set in VS2010?

That is, in VS2010 I set the height of the window to be AUTO (so it should be just high enough to contain the controls) and this seems to work visually within VS2010. But when I then run the application the window height of the app is much larger开发者_如何学Go than this?

Have you tried setting the SizeToContent property of the Window to WidthAndHeight ?