Comment 20 for bug 259244

> the zoom keys now register correctly in /lib/udev/keymap -i input/event4

Great, thanks for testing.

> Also I've noticed that the skip and fast forward buttons are both recognised as the same key, xev however seems to see a difference between them (below)

Hm, I din't see a significant difference. It just shows that X.org doesn't recognize those keys at all (no KeyPress/KeyRelease events), due to these key codes being > 255.

> is there any way to utilise these keys even if they could be mapped to a keyboard character.

You could change the keymap (/lib/udev/keymaps/logitech-wave-cordless) to assign any other key you like which is smaller than 255. Please see "grep KEY_ /usr/include/linux/input.h" for available keys. To avoid overwriting your changes with the next udev package update, you can create an /etc/udev/rules.d/96-keymap.local with something like

  KERNEL=="event*", ENV{ID_VENDOR}=="Logitech*", ATTRS{name}=="Logitech USB Receiver", RUN+="keymap $name 0xD4 nextsong 0xCC previoussong"

to map the zoom keys to KEY_NEXTSONG/KEY_PREVIOUSSONG (for example).