Period key to center rotation?

I used to be able to press the period key (I have emulate 3 button mouse and emulate numpad on in prefs) to center the rotation around the object I have selected.

However it doesnt work at the moment have you come across this issue before? I think im just not understanding the steps here, I select an object in the scene and hit the period key, at that point the 3D manipulator (xyz axis) jumps to the 3D cursor. I dont want that to happen. why does it keep doing that?..even when I do finally get the manipulator to sit in the middle of the selected object (by hitting the comma key) the rotation is not around that object.

using mac.system-info.txt (16.5 KB)