Audio problem: In Part 3 when the Brigadier gets behind the sand pile with Arthur Ollis, the Brigadier asks him "Did you find a way in?" This is not Nicholas Courtney's voice for this one line. He speaks again right after that and it is his voice. (00:13:20)
Audio problem: When the companions are returning to Earth via the pillar of smoke, you can see and hear each person walk up the steps and then supposedly disappear. Unfortunately, you can then hear them walk down the other side of the steps..
Answer: It was never destroyed on-screen; it was intact at the end of the TV movie, and destroyed by the start of the 2005 series. It was destroyed in the novel "The Ancestor Cell," but in a completely different manner to what happened in the series.
DaveJB