doubleofive said:

If they recomped all of the lightsabers, why are these still there?

http://www.thelightsaber.com/web/Goofs/ANH/anhgoofs.htm

Some of those are things they wouldn't have changed, but there are some terrible mistakes in there.

I don't think they recomped all the lightsabers, I just assumed they had recomped that particular scene as it looks quite different to the original effect, in a bad way. Yes, it's subtle but I noticed it from the first time I saw the SE and I'm still not sure what they did. To be extra picky, removing the additional grain in this scene is an alteration in itself, it's part of the visual effects technology of the time just as mattelines are. But whatever...

That goofs-list isn't entirely correct in its information, the lightsaber in the Falcon was blue originally, it's only later video transfers that made it look white or green. People forget that these films were beautiful when they first arrived, not that strange really, as these films only looks worse for every release they get, sad really.