Comment # 4 on bug 1044777 from Stefan Hundhammer

What do you mean "freeze"? What exactly happens? 

Does CPU usage go up? 
Does RAM usage go up? 
Can't you move windows around anymore? 
Can't you start any more new windows?

Somehow you managed to make screenshots, i.e. it doesn't appear to be a real
freeze of the desktop.

I suspect that the kernel change log is simply very large, and it takes a while
to load the data and populate the widget with it. That would mean that CPU and
RAM usage go up, but after a while everything will settle down.