I dont know whether this solution is isolated or not. Anyways dont want to start an arguement. Repairing/Fixing disk permissions solved my problem. Now audio works perfectly. Try that. It doesnt cost you anything.
Thanks a lot for your guide. Worked perfectly on my GA-B75M-D3V like a charm.
Everything is working fine.
ATI 5770HD works fine on dual display
Sleep/Restart/Shut down working fine.