I read about it here: http://web.archive.org/web/20140924201932/http://secrethistoryofstarwars.com/natureofthebeast1.html

When Lucas finally flew in from California and saw the rough cut he was horrified and scrambled to re-edit the film to be more like the way he envisioned--action-oriented, eliminating subtlety and moving from scene to scene as fast as possible;[60] again, very much like the editing of the prequels. His cut was a unanimously decreed disaster.[61] Kershner then recut the film with Lucas and it finally became we entity we know.[62]