Symptom
Sound functions as expected after you turn the computer on. This can range from a few seconds up to 30 minutes. After this period, the computer makes no more sound until it restarts or wakes from sleep.
Sound functions normally when started up from Mac OS 9.x.
Note: This issue has only been reported on this hardware configuration.
Solution
Install Mac OS X 10.0.3 Update or later to resolve this issue.