I am also experiencing this after longer concurrent playtime (approx 90mins+), reproduced the issue as per haddockd procedure on the previous page. Tested multiple builds, using both analog X-Fi and passthrough spdif to a external decoder off the integrated realtek but no difference.
Win7 64bit SP1
i5 2500k 5Ghz
8GB 1600
GTX 570
Win7 64bit SP1
i5 2500k 5Ghz
8GB 1600
GTX 570