I'm just starting to try out XBMC (from the ubuntu repo) and noticed that it's using a lot of CPU when running fullscreen, even when I'm not playing a movie. There's a definite lag even on the home page with the scrolling footer.
I've toggled the option to use it in windowed mode and it seems to be a lot more responsive. The footer lag seems to be gone.
Does anyone know why this is happening? I would have thought that running fullscreen would have used less resources.