The clock drift calculations within the current version of Audio Render result in the clock used for driving the reference clock being the system clock. In most circumstances this is OK as the differing clock rates between the system clock and the audio hardware clock can be measured and used to correct the calculations. On some machines this measurement is not correct which results in the sync between the audio and video drifting.

h4. Steps to Reproduce
Specific hardware needed (See Gibman)

h4. Additional Information
The clock used in the main calculations should be the Audio Hardware clock rather than the system clock. This has knock on effects for the smoothing of the reference clock and so needs extra rework to solve the problem for all users.

A Basic test has been used to confirm the problem and a solution. Gibman and others have run the test binary and confirmed that the Sync problems are solved.