Using a Wacom Cintiq and an Intous. It's not the Wacom obviously, and it's not the keyboard (spacebar will work in every other application). Restarting Photoshop does not fix it, I have to reboot the computer. The problem happens randomly but also seems to be associated with hitting the F key to go to a different screen mode.
I've tried deleting PS preferences and I have the latest and greatest PS updates, Mac OS 10.10.1. This problem occured before I upgraded to Mavericks, so it isn't that either.