I also heard the rumour about John Williams writing Lucas a letter essentially disowning the score for TPM as it appears in the film. I don't know if I believe it or not, but it certainly wouldn't surprise me considering how badly the score is butchered in that film. The scores of the OT always flowed, and they certainly never got cut off mid piece to insert a different theme for a different scene. That was part of the problem with the SE's, they messed up John Williams original score. In the prequels it's like George stopped caring at all, all three movies are an ugly hack and slash job with the music just cobbled together. After TPM I get the distinct impression that JW washed his hands of the process basically only wrote a few unique pieces per film and let George fill in the blanks with the incidental music from TPM.
I wish I could remember where I read about that letter, I think it was AICN.