Harmy said:

In all pre 2004 versions of this shot, the stormtrooper passing near the camera seems to have been affected by some composition error where something was scribbled over one of the composite elements. Check it out, there's clearly a sign saying something like B FFET 23 over his path:

As I have nothing more productive to do in my free time I decided to check this out and to me it looks like the line in the middle says: B PFTT. 23

The glare from the stormtrooper helmet in one of the frames makes the T look like an E. Under it, it looks like it says B-7 or 3-7, the line above them is impossible to make out but there seems to be a letter M in there. Something like this:

M
B PFTT. 23
B-7

Someone should make a t-shirt of that. :)