I've a MacBook Pro 17" (Mid 2010) running Mac OS X 10.6.5. I'm wondering why it doesn't switch back to the integrated GPU when running on battery and no external display is attached. The check box to automatically switch graphic modes in Energy Saver preferences is checked of course. I'm running no games, just productivity apps.
At least System Profiler lists the LCD display under NVIDIA and not under Intel HD Graphics.
How can I debug this?