Does anyone know how to reset a Direct3D device after alt-tabbing out of fullscreen mode and refocusing the app? I tried a CheckDevice method using TestCooperativeLevel() and a DeviceNotResetException catch in my gameloop, but it isn't working. The app still bombs out w/ a message about not being able to reset the device. I also tried messing w/ the DeviceReset event... I'm pretty much stuck now, and the Direct3D samples aren't very helpful (not fullscreen).