I have a copy of WinDVD 6 Platinum. I'm using analog out (front, back, and center) channels. I can play DVD video with surround tracks just fine, and all 5.1 channels work. However, I attempt to play DVD-Audio discs, and only the left, right, center, and sub channels work. No real sound.

Any ideas why this might be happening? And I know for sure the disc is in surround.