Mac OSX Yosemite Wacom Intuos 4 - Painting not possible due to terrible brush lags

Question

I recently updated my iMac (27", end of 2013, 3,5 GHz intel core 7, 16 GB Ram + Nvidia GeForce GTX 780M 4096mb) to OS X Yosemite, and also installed the new driver for my wacom intros 4 tablet (version 6_3.9w5).
But since OS X 10.10, I got nothing but troubles with CS6 (version 13.0.6) - whenever I try to paint with a brush (it doesn't matter which one I choose), the stroke gets applied laggy and delayed. I already installed the white windows plug-in but nothing changed.
When this happens and I try to quit PS, most of the time it says the program stopped working and I need to force quit it.
When I use my mouse in PS, on the other hand, every stroke is fast and smooth as it used to be.

Answer 1

I had the SAME problem. This worked for me:
Before, I was running Yosemite 10.10 on an iMac i7
I had the latest driver from Wacom (I tried a couple of older drivers, to no avail)
I'm running PS CS6, with all update
I'm using a Wacom Intuos 5 medium tablet
I was getting super bad lag while using the brush and other tools. Let's say I'd open an image to edit. After selecting the keyboard shortcut for my brush, I'd make one pass with the brush on the image. The brush stroke would be there, but it wouldn't show up in the history palette. Only after making another brush stroke would the previous action be recorded in the history palette. I was lagging real bad. In between brush strokes I wouldn't be able to change tools or even change the size of my brush. Nothing worked. I'd have to click off the image to regain control, or click the trackpad to regain control. BTW, the trackpad worked perfectly. NO lag for anything in PS. The polygonal lasso tool, one of my favorite selection tools, was basically unusable with the lag. I'd have to click several times before it would catch up and then sometime it would just randomly close the selection. So that was useless.
Ok, so that's what was happening to me. My tablet was basically useless. It took triple the time to work with it.
All I did was update Yosemite to 10.10.1 and the tablet now works PERFECTLY in photoshop cs6 for me. I'm not sure you'll get the same results but it worked for my computer. I really didn't think it would work so I was pleasantly surprised when it did.
I had tried installing older wacom drivers. Didn't work.
I tried reinstalling PS CS6 in a new user profile on my Mac. Didn't work.