The only one I can think of off the top of my head though is right before Luke confronts Vader, in the Carbon Freezeing Chamber, you hear a "gong" from an abandoned music cue that scored the fight scene between Luke. Wisely, Lucas chose to not score the LS duel, but you can still hear a remnant of that cue when first Luke rises into the unlit freezing chamber right before Vader says "the force is with you young Skywalker,...." This cue is out of place, and just sounds stupid.
Although, these screwy cues are techincally part of the OOT they are legit screw-up's, none the less, and if your interested in doing little things like reversing Pietts credetials to the correct side of his shirt ect ect, I just thought I'd bring that to your attention.
All the music cues were corrected for the SE release of ESB.