On Sat, Aug 27, 2011 at 5:54 PM, Marcel Korpel email@example.com wrote:
As I do not get replies to my forum post , I'll try asking this question here.
Up until recently, I used to get the zoom slider on my Microsoft Natural Ergonomic Keyboard 4000 working by following the instructions in a Gentoo Wiki page . In short, by applying a small patch  to my custom compiled (ZEN-)kernel the keycodes of the slider are changed to values below 255, enabling the X server to process those keycodes.
I suggest reporting the problem with your keyboard upstream so that they can fix it properly and your patches will no longer be necessary (otherwise they are bound to break again).
Unfortunately, after a recent kernel update I get different keycodes, as if the patch isn't applied at all, although I can confirm that include/linux/input.h is still changed. My keycodes now read:
$ showkey keycode 418 press keycode 418 release keycode 419 press keycode 419 release
I flipped through latest kernel changes of 2.6.38.x  and 2.6.39.x  (that I currently use) but was not able to find a change that might have influenced the (translation of these) keycodes.
What was the last working kernel, and what was the first broken one? Did you try cloning Linu's tree and doing git log <known good>...<known bad> -- include/linux/input.h