I have an issue with clone mode.
The sound is only one of the two hdmi displays.
I have one pluggued on hdmi output of the video card, and one on the DVI with a HDMI adapter.
Sound works on both outputs when only one display is active, but is only on one of the display in clone mode, depending wich one was active first.
So DVI->HDMI adapter shouldn't be the issue.
Also when DVI->HDMI display is active, if I plug the second one then a message display, saying that I will not have sound on the DVI->HDMI display because i use an adapter, however I still get the sound on this one, and the one on HDMI is the one without sound.
Also you have no way to choose wich one outputs sound, so there is obviously a bug.