I'm running slackware 12 KDE 3.5.7 (actually Backtrack 3 liveUSB version) on a Lenovo T400 laptop. I want to create a keyboard shortcut to perform an input action command to raise/lower the kmix volume when the laptop multimedia volume buttons are pressed.

The dialog that listens for my keyboard input will only register the normal keyboard keys. When the multimedia keys are pressed, I see the dashed rectangle (showing the focus) disappear indicating that a pressed key was detected, but the keypress doesn't register (apparently because the multimedia keys aren't included in the standard mapping table???)

Another way I know the multimedia keys are detected is because I see output when pressing them while running this command:
od -tx1 /dev/input/event4

How can I get those special multimedia buttons to register using the keyboard shortcut configuration dialog?

Does the application "xev" register your multimedia keys, and if so, detect a name they have? If they don't have a standard name, this is probably why it doesn't work. You can use xmodmap to assign them a better name based on the information from xev.

That was what I needed! I found the following excellent article which shows how to configure the unconfigured multimedia keys:
http://cweiske.de/howto/xmodmap/allinone.html

After running "xmodmap .Xmodmap", they work by default, but the XF86AudioRaiseVolume key raises the volume by too much (11%). I'd like a smaller value like maybe 5%.

What is the configuration file that contains the volume change amount settings?

That seems unusual, as mine is raised by 5%. Is the keypress being sent twice perhaps?

No, this happens on 2 different systems that boot off the same USB based OS. There's nothing to indicate that the key is pressed twice, also twice of 5% is not 11%... I would love to find the configuration file for the percent change.

If you try with a new user, or if you remove the KMix configuration, does this occur?