Video Mania - S3-E6
Plot hole: The plot for this episode is that Mark reluctantly tries out video games for the first time and soon becomes addicted to them. However, the season 1 episode "All in the Family" showed him to already be an avid gamer.
Audio problem: When Cody is playing the blues on his guitar, he is shown to be fretting the higher pitched strings while playing the lower strings open. However only low notes are heard and at least three different chords are heard, which would not be possible if he was playing the strings open.