I'm glad you started this thread Jim, because just today I was thinking about Here's That Rainy Day. When we first learned that one about 6 years ago, we checked both the first Real Book, and the New Real Book (it is in F in the first, and G in the New). There was also a version of the tune by Melvin Rhyne (in F, IIRC) that we referenced. Also, at the time, Jim was studying with MI pianist Gary Shunk, who apparently agreed with the RB changes. We've been playing that tune ever since.
So earlier this year, I played it with another organist, backing up a singer. I asked her what key she sang it in, and she said C minor. I was confused by the minor, as we've been playing it in major. Sure enough, it was in Cm. Afterward, I questioned the organist about (a brother, very wonderful player, too) and he was adamant that it was a minor key song. I mean he was about to get up in my face about it - "Man, I've been playing that song for 10 years, and I ain't never heard of it in a major key!" All right, all right ...
So what gives? Are there two sets of changes to Here's That Rainy Day?