For binding multimedia keys I would recommend a third party utility called Winmapper available at http://www.spinner.nl. It was designed specifically for the purpose of creating hotkeys and rebinding multimedia keys, with and without modifiers. You can bind it to litestep command using bang.exe or litestep.exe [bang command]. You would have to disable intellitype to use winmapper though, the two *will* conflict if you try to run them both at once.