A couple of things...Then they should have definetly fixed it up, when they first dubbed the episode a few months ago.
- Maybe they didn't catch it. Truth be told, till it was pointed out to me when the episode originally aired, it didn't cross my eye (but it was a very low-quality first airing).
- Maybe they see it but ignored it. Really, does it have THAT much of an impact on the episode in the long run? No, especially not with an episode most people brush off even after viewing (which is a shame, since it sports good animation and funny gags).
- Why should they be responsible for cleaning up the mistake of the original? Unless the animators have since then gone to clean up the error for the DVD release or whatever, then I could see a request of the fixed episode or a touch-up job. The ability to not make edits to the show aside from voicing and music is a bit of a double-edge sword: we don't get the crazy edits, but we may not get the fixes to the stupid errors either.
By the way, I really liked the episode (even originally), and I'm glad they kept one of my favorite pieces of music even though the didn't have to keep it. Thus, I'm satisfied.