How to toggle Aero Glass on and off in Windows Vista

Thanks to Robert McLaws for commenting on this post to correct me - the following information is obsolete - please ignore!

Very weird I know but the key combination you need to switch Aero Glass on / off (given that your system's configured for Aero Glass) is Control-Shift-F9

I'm sure there must be a rational explaination as to why such a combo but it's beyond me!