I have no idea what I did or what changed, but now when I'm modeling and I select a control point or group of control points, and then go into turn mode to rotate the view, the view does not rotate around the selected control points, but rather around the center XYZ origin for the entire modeling window.
This may or may not have anything to do with it - I noticed the change after installing v18k. I doubt this has anything to do with it, since I uninstalled the whole program and then installed the version I had previously, v18j, and I'm still having the same problem.
I have an old CD version installed as well, 11.1, and I do not have this problem with it.