These may be of some interest you on the subject of Vader’s ‘No’ scene…

Star Wars coming to Blu Ray (UPDATE: August 30 2011, No! NOOOOOOOOOOOOOOOOOOOOOOOO!!!)

2011 SE : The changes to the OT films & general 2011 Special Edition discussion thread

and you’ll probably find more threads on the subject in An Index + ‘Info & Help’ Thread for… Original Trilogy Discussion and An Index + ‘Info & Help’ Thread for… Theatrical Cuts vs. Subsequent Releases

Good luck with it, mate. 👍

PS - it may be worth asking a moderator to move your other OT-based threads into the Original Trilogy section of the site - they’ll likely get more views and discussion in there.