I did a fresh install of Ibex on my Dell E1505. Install went smoothly and whatever little thing was not right I have been able to research and fix. Until this. When I press the volume buttons on the front panel, it only shows the current volume level on the screen, but will not adjust it. When I open KMix, I see that the buttons adjust the PCM level and not the volume. Two things, what is PCM and how do I get the buttons to work the volume?