There are two alterations to the original footage of the running gun battle between Han and Chewbacca and a group of stormtroopers that I feel the need to discuss.
First, when Solo acts quickly (with lightning swift death, like a true hero would...?) and surprises a party of troopers into fleeing.
He and Chewbacca chase them for a ways down a hall, but when they come around a bend the troopers have regrouped.
They repulse the smugglers' charge and chase after them.
In the Special Edition a digital backdrop has been added that shows many more troopers and a hanger in the background with TIE fighters hanging from the rafters.
Why?
To make it look like the only way the troopers could charge back at Han and Chewie were with reinforcements?
Or to strenghthen Han and Chewie's image ('we wouldn't have run away except there were fifty more stormtroopers behind 'em')?
Second, in the original we see a set of 'blast doors' closing (no doubt a failsafe feature in the event of BLASTERS going off in the hallways) and one of the troopers yelling,
"Open the blast doors! Open the blast doors!"
In the Special Edition a voice over has been inserted just before this of a trooper (the same one?) ordering,
"Close the blast doors!"
What the hell?
An obvious attempt to make the troopers appear comically disorganized and stupid.
This bit of over-dubbing doesn't even appear in the 'Annotated Screenplays', though Threepio's does.
A couple of low-class editing tricks.