It's the green button that minimizes and places the window. After initially minimizing and placing the iTunes window in the lower, right-hand corner, subsequently pressing of the green button should enlarge the window, and another press should again minimize and replace it to its previous spot. However, it will only replace it to the right-hand corner leaving enough space below for the dock to be extended to the corner, which in my case is NEVER extended to the corner because I prefer my minimized iTunes window there. BTW, it exhibits the same behavior in the left-hand corner.
I get that some programer thought that the entire bottom line should be reserved for the dock, but that has always been available to the dock by placing other windows above the dock. It just seems to me that they took away some flexibility with this latest change. I was hoping that some one had a software fix.
Placement of other windows is not a problem, and this iTunes behavior only began after upgrading to Version 9.2. I did redo the finder preferences, but that didn't solve the problem.