oh, i think I wasn't clear. The TV is my monitor. The sound system is basically my pc speakers. We use the PC for 100% of our entertainment so no need to use the system as anything else. However, as things always happen, I believe i may have solved the issue and I'm waiting for the cable to test my theory. S/pdif is something I have never used or really even knew about until now and I suspect that if I run that instead of HDMI, it will solve the issues.
Sound > PC > TV and I'll worry about other sorts of connections if they come up. I'm going to feel real stupid if using this connection fixes the problems after on and off working on it for a week