I have a Microsoft Wireless Keyboard 3000, part of a wireless RF keyboard/mouse bundle, which comes with several media keys (Back, Forward, Play/Pause, Vol. Down, Vol. Up, Mute, Home, Search, Mail and Calculator). They worked perfectly in Hardy once I got all the keysyms straight in gnome-keybinding-properties.
Since updating to Intrepid beta (via update-manager), none of these multimedia keys work anymore. Apparently, no KeyPress/KeyRelease event is generated when they are pressed (checked with gnome-keybinding-properties and with xev). Further, I have gone as far as to go to a (tty) console and use 'kbd_mode -s' to see the raw input from the keyboard (thankfully I remembered about SysRq+R before rebooting ;)), and the multimedia keys do not generate any.
I am using the Generic 105 keys international distribution, which used to work perfectly under Hardy. I have also tried many other possibilities, including every Microsoft-branded keyboard in the database, several unrelated models and some of the generic keyboards (including the "Evdev-managed"), to no avail.
I have seen several other similar bugs, but none of them related to exactly the same behavior. I am using Intrepid beta, up to date.
(This was written by somebody else, erasing the original description in the process:)
Microsoft Wireless Keyboard 3000 user here. Confirming this is indeed a regression. I didn't realize how much I relied on the special keys until they disappeared! Would appreciate any insight into why this regression occurred, in addition to what might be done to fix it.