And not "Standard Definition" button - but does the "Before" - "Back" - "Minus / decrease resolution"! "Increase resolution" Only the key works and increases the DPI mouse.
Have it first in the "Logitech Gaming Software" with different profiles and key functions tested (including software reinstalled). Then I tried the mouse to other computers (Windows 7/8), but the buttons above do not work anyway (whether with or without "Logitech Gaming Software")!
If these keys would work, I'd give the product 5 out of 5 stars because it is otherwise truly a great mouse. Price / performance would be also very good!