Yeah,
I finally solved the problem.... Not sure if it was a clever solution, but anyway...

Go to the alsa webpage:

http://www.alsa-project.org/

and download the source code version: 1.0.14rc2 of newer. If you are lucky, when it comes to you to solve this problem, there will be a rpm available somewhere... You can try to search for it in: freshrpm or rpm.bone.net, etc...

Remember to download the source packages for everything alsa related:

alsa-driver, firmware, lib, oss, plugins, tools and utils

now check which of these you have installed on your system:

rpm -aq | grep alsa

Uninstall everything but the alsa driver with:

rpm -e --force list_of_alsa_packges

Then do the usual to install from source each and all of the packages you downloaded. I mean, open the packages:

tar -xzvf package.tgz

... and follow the installation instructions inside each new directory. Once you have installed all the packges, restart the window manager (CRTL+ALT+BACKSPACE) and cross your fingers. You should have
new options in the kmix window and a working microphone!

DRAWBACK: now the mute multimidia button controls the master volume and not the PCM volume so mutting does not work

NOTE: at first I uninstalled all alsa packages from my system and then installed from source all the latest versions. That works. However, I had to use a script inside the alsa-driver tree to create the sound devices (/dev/...)... but the configurations and devices only lasted until next reboot... so I re-installed the old alsa-driver with the suse rpm and then re-installed (overwriting) the latest version (I tried to have the device' script running during boot but it did not work).