Wacom, circles as squares issue

Dear all,

I have a:

• Wacom Intuos Pen & Touch CTH480.
• Using: http://cdn.wacom.com/u/productsupport/drivers/mac/professional/WacomTablet_6.3.9 w5.dmg
• Adobe Photoshop CC 2014.2.1.
• Mac OS X 10.10 Yosemite
• MacBook Pro (Retina, 15-inch, Late 2013)
• Intel Core i7 2,4 GHz + 16GB RAM + 500 GB SSD
• Intel Iris Pro + NVIDIA GeForce GT 750M

I had removed and reinstalled the Wacom drivers following the "REMOVE" steps from the "Wacom Table Utility".

I'm using my tablet with the original provided USB cable. I also tried using another USB port on my computer. I don't have any other device connected to my computer. I have also my Magic Mouse (Apple Bluetooth mouse) turned off. Also I'm using the original provided power source and I also tried using the computer unplugged.

But I always get the same results.

It's like I always get squares instead of curves.

I also tried using a ruler, and as you can notice, if I do fast strokes: I get almost perfect straight lines.

But if do slow strokes or back and forth strokes, the lines get jagged.

Attached are the results of my test. Also notice that I had reseted my brushes and I'm showing the settings in the brushes I'm using.

I had tried to rotate the tablet to check if the problem was my hand or the way my hand do circles, but as you can see on the attached JPEG: that's not the case.

Here are some more links of people describing similar issue, but I cannot find a solution for MacOS:

https://forums.adobe.com/thread/1312521

http://forum.wacom.eu/viewtopic.php?f=3&t=14584

http://forum.wacom.eu/viewtopic.php?t=17102

http://www.yjstudios.com/blog/2014/05/08/how-to-fix-the-wacom-cintiq-from-shaky- jittery-wobbly-jagged-lines/

http://osu.ppy.sh/forum/t/175442

Any other ideas what could be wrong?

Thank you.

Kind regards,

Juan Pedro