In a couple of the color episodes (The Lodge was one) Andy calls Burt Mustin 'Burt' altho Mustin is listed as 'Jud' in the credits. In one color episode (Helen's Past, I think) Opie refers to his father as 'Andy' instead of 'Paw'.

Can you think of any others goofs?

Good observation.

Barney's hair goes from being combed to messed up to combed again, as he tries to say the Preamble to the Constitution.

Barney, Goober, Gomer, and Otis.:winkgrin

in a black-and-white episode (the one where Andy hires an intern) Andy and the intern walk into the courthouse. They show them from the outside of the building; going through the door on the left. Then, the camera shows the inside and they're coming through the left door again-when it should be the RIGHT door!