THX 1138?

While it is somewhat similar to Stanley--I think the comparison ends there.

The only two close connections between 2001 and THX that I've noticed are all-white sets, and the final chase in the tunnel has some visuals that slightly resemble the star gate trip in 2001 because of the the way the shots are framed. I just posted the trailer for THX in the Amphitheatre's Trailer thread (see my signature below) and that's where I noticed the connections.

On the other hand, every film school student in the world who was studying when 2001 came out was probably influenced by it in some way or another, so what's wrong with Lucas showing he was affected too? It's very brief.