Both this one
Dialogue Difference 5 29:46
When R2-D2 is being loaded into Luke's X-Wing, C-3PO says "and" before saying "do take good care of yourself."
and Lando's line "We're sure in the middle of it now"
are in the original theatrical mixes and in their '93 THX remastered tracks, those lines are just mixed lower in volume compared to other mixes.