The Secret Box / Band Geeks - S2-E14
Audio problem: At the end of "Band Geeks" when everyone is playing "Sweet Victory" at one point Mrs. Puff is shown playing the guitar. When this happens, you can see the others in the background not doing anything, even though their instruments are heard.
Guilmon Comes Alive - Part 1 - S3-E1
Audio problem: When Jeri starts miming with her sock puppet, it is sometimes out of sync with her voice. It is most noticeable in the part where Takato has detention.