I don't think that Yu-Gi-Oh! R had a release in January. The third volume was just released last week.
I'm also really surprised that the forth volume of GX did that well. I've heard who the manga still sells, despite the fact that the show hasn't been on the air for awhile, and that's pretty cool to me. I'm glad that I bought a copy as a early birthday present. It's also nice to see One Piece on the list.