Hi I had a quick look through the forms but couldn't see anything similar to my issue here.
I use PS CC for a lot of illustration using the brush tool, I'm constantly switching between brushes, zooming and eraser with keyboard shortcuts.
My problem is that i'll draw quite a bit with the brush and then goto switch to the eraser clicking E, it doesn't switch immediately, I'll have to then draw another little bit with the brush and then click E again and it switches, same thing happens for zooming in and out using shift > + it just wont do it until I draw an extra little bit with the brush.
I'm assuming it's losing focus on the photoshop pane or something as i'll occasionally get a black blink as I'm scrolling around or drawing, maybe every few minutes.
I'm running this on a late 2013 15" Macbook Pro, OSX 10.9.1, 16GB RAM and Quad 2GHZ i7.
This Macbook is two weeks old so have no third party plug ins, haven't evne downloaded any new fonts yet, CC is fully up to date. I'm using a Wacom Bamboo to draw with.
I also run PS on my iMac late 2011 with Mavericks and it does the same thing.
I've never had CC with Mountain Lion, but my old CS6 used to run fine when I had Mountain Lion on my iMac.
Bump. I also have this issue, running Photoshop CC on a brand new Macbook Pro with Mavericks. Using a Cintiq 22HD, and the program randomly refuses to accept any keyboard input. Tool shortcuts, hotkeys, command functions, nothing. I have to click somewhere on the program to get things ticking again. Almost like it's losing focus, without LOOKING like it's losing focus.