Mr. Walsh Goes to Washington (2) - S4-E32
Audio problem: During the scene where David and Babyface are talking and Babyface asks David to fill in as one of the keyboardists for his carnival show, the camera shots going back and forth from both behind David and Babyface show them speaking, but it is very clear their words don't match their lip movements.
Radar Love - S4-E12
Audio problem: During the scene where Dylan and Kelly excuse themselves from the Walsh Thanksgiving dinner to go argue in the frontroom, pay attention to the camera shot behind Dylan when he is telling Kelly that he "just happens to like Cindy's Thanksgiving turkey better than your mom's." His lips do not match what he is saying.
Emily (a.k.a. The Pink Pearl) - S4-E13
Audio problem: During the scene where John Sears and some of the keg brothers are telling Steve that one of his hazing duties is to steal Professor Randall's signed baseball, pay attention to the camera shot behind John Sears when he is talking to Steve - his lips do not match what he is saying.