Looks like the 2nd episode of the show has a different arrangement and/or different part of the song. I like this one quite a bit better.
http://www.youtube.com/watch?v=-aSMC74zuXQ&t=0m8s
Is this a mini-series? There might be a different part of the song for each episode and the actual single probably will sound different than any of the individual excerpts that they use for the title sequences.