Comment 21 for bug 351990

I did some research and come to this conclusion:
On Kubuntu Alpha 6 everything worked fine, but with beta came kernel update and that is the time when problem has start to show up.
I tried to use Compiz and worked flawlessly.
Also when using Compositing type: XRender don't have any problems with randomly freezing.
Hope this help to someone who is smarter then me, and solve the problem.