Dockingstation audio jack (port replicator)

I finally found out how to get sound out of my port replicator when my Latitude D610 is docked.

Go to the volume control (speaker icon next to the clock applet) and right click it. Then under File -> Change Device, select "Intel ICH6 (Alsa Mixer)". Then go to the Switches tab and turn "IEC958" on

There! :) Now I just need to automute when my screen is locked. If I don't, my colleague switches off my speakers...