Joshua_Blue said:

A new idea (just a test video, audio/video not perfect):

http://www.speedyshare.com/gRpvV/test3.mp4

I have moved the 'This had better work!' scene and combined it with a later scene of Tarkin and Vader

It actually looks quite ok, what do you think? How I see it now, Tarkin has doubts about Vader's tracking device idea, but we are now already orbiting the planet and Vader calmly (and over confidently) rejects the worries, as if he knew all along it was going to work...

My only issue with it is that Tarkin is specifically referring to the tracking device when he is asking if it will work, yet they are orbiting Yavin, meaning they've already tracked the device to a set location, which would imply it DID work already, so why would Tarkin ask about the device being on the ship?

However, the two Vader/Tarkin shots do match up quite well, as if they were filmed as one scene and edited into that clip intentionally.

Maybe if the conversation were a bit more focused so that the doubt is about the system, rather than the tracking device, it might work. It could go like this:

Tarkin: "I'm taking an awful risk, Vader. This had better work."

Vader: (from ESB) "That IS the system." which then resumes back to "This will be a day long remembered..."