I have a mac mini 2011 with OSX Lion. And I have connected my monitor (with integrated speakers) through hdmi port. The sound is working fine, but the volume keys on the keyboard don't work. When I press one of them the volume image appears on the screen but with a prohibited signal.
Is there a way to fix this and make my keyboard keys change the system volume?
By the way, they work very well when I use another audio output device