Huh... I'm getting the same error, actually. They have what has got to be the worst Flash-based interface that I have ever seen, but what appears to happen is that it flips through the list of chapters briefly (displaying a QT ? for each), then when it runs out it ends up at the can't play graphic.
Same in both Camino and Safari on 10.5.2, latest F4M (paid Pro version, actually). Interestingly Firefox will occasionally play the ads or TBS graphic, but then gives the error when the actual program rolls around.
I wonder if it's because of Windows Media content protection--I'm pretty sure Flip 4 Mac has trouble with that--or if it has something to do with the way they're redirecting between ads and the actual video.
What browser is this working on for you, Hankster? (And are you sure you're seeing the actual "whole episode" video, not just the ads before it?)