So, here is the solution to my problem. After seeing that Jeff's suggestion worked in APEX 4.2.3, and knowing my version was 4.2.2, I upgraded my version to 4.2.3. The Select Lists worked immediately as expected.
Would this have worked in 4.2.1? Was a bug introduced in 4.2.2? I don't know.
Thank you, everyone, for you time on this one.