I have an Acer Revo md which has no sound over HDMI (was working until recently). So I followed this thread.
I upgraded the core yesterday, removed the md in web admin, ran /usr/pluto/bin/Diskless_CreateTBZ.sh and then turned on the Revo MD. Everything seemed normal during creation but no sound over hdmi no matter what I chose in AV wizard (HDMI, DVI-HDMI2 etc).
I just upgraded the core again and got another pluto-boot-scripts update. Rebooted the core. I have again deleted the new md, I am currently running Diskless_CreateTBZ.sh again and will let you know what happens when I turn my md on.
My output from the pciid code in this thread is 087d.