One really annoying difference between 2.6.10 and 2.6.12 on the Mac is that now if I hold down an arrow key on the keyboard, it doesn't update the position continually. Instead, it waits until I release the key and then it flips quickly through a bunch of previews.
This makes it more time-consuming to find the places I want to cut.
Kindly report current Operating System and version on your mac? The developer(s) crystal ball broke :P
OS X 10.11.4