The first time I ever booted the VM I had working HDMI sound out, upon the 2nd and all subsequent boots it was dead, so went with the DVI-Adaptor (it only cost me £2.50 on eBay! ).
If I boot still directly connected to HDMI sound is then gone, do a another cable swap to/from the DVI adaptor all is ok via HDMI again. The weirdness is that if I boot up the VM with the DVI-HDMI dongle as the output and change the output to HDMI sound continues to work (with or without soundflower/soundflowerbed audio routing). I would like to liquid cool my 750ti but the Arctic Accelero Hybrid III-140 here is more than i paid for my 750! Exactly what is the sound weirdness you are getting. Also did you ever try some different vbioses passed through to see if you can change the default sound out port? Nice looking build by the way! Um its a shame the soundflower tip doesnt work.
