It's fixed now! Debugged.
I'm not hearing the echo now. Looks like it's debugged!
The audio seems to have a bug starting at 40:33, when the BBC announcer says, "I sensed a certain pride in his answer..." There is an echo starting then and continuing for the next few minutes. It seems to be most pronounced on HAL's voice, but it's not just for HAL. I hope this bug is fixed soon, because John Chu is right, it becomes unwatchable at that point.