I'm working on an XNA project that doesn't use the built-in Game class, mostly for learning purposes (so I can mess with different game loop types, etc). It's only designed for the Xbox 360, because the hardware is consistent and I don't have to worry about compatibility among different PC hardware configurations.

So far, it's working well and I can clear the screen to a color, but I'd like to make sure I handle the GraphicsDevice correctly before moving on. What exactly is the life cycle for the GraphicsDevice on the Xbox 360? Is it ever lost or reset automatically? I know that on Windows, it's lost when the window loses focus, but the Xbox obviously doesn't manage focus. It appears to even keep the graphics device when the Guide pops up, which is the closest thing I can find to "losing focus" on the Xbox.

I'd like to think it's simply a matter of "fire and forget," which would make a lot of other things much easier (only needing to load content once, for instance). But I want to make sure.