I'm using a Radeon 5450 with my Onkyo TX-SR606. I just got this receiver, so I connected the card via HDMI.
For the most part I have no problems with DTS-HD bitstreaming in PowerDVD, but I do have a problem with LPCM sound.
With LPCM sound there's a buzzing sound all the time, and other sounds while I maximise/minimise windows, or even change the receiver's volume level. It goes away when any bitstream starts being passed through, but it stays on when I...