You can also hold the Control key down and left-click-drag the stats. Right-click is reserved for context-sensitive menus throughout PT4, as it is in most applications these days.
You can "unlock" stats from the PT-icon menu - click on the right hand side of the PT-icon which appears on your table. Right click is now used for context sensitive menus, as once you have positioned your stats you will not need to move them very often, but may want to interact with the stat groups more often. This also matches functionality throughout PT4, and most other applications.