Audio problem: In "Silly Love Songs" during the final song You can hear Blaine singing "I can explain." but in a couple of the shots he is lip-syncing to the "I love you". Next shot is he is back to singing his solo part.
Economics of Marine Biology - S4-E7
Audio problem: Coach Chapman makes his way up to the white board to introduce himself and the class topic. We hear him say "Welcome to P.E.E." but his mouth doesn't open at all.
Audio problem: In the final scene when Cleveland says to Terry "I'm gonna get paid and you're gonna get laid", they both start cheering. But when it comes to the wide shot, Terry is still cheering but his mouth isn't moving. (00:19:55)