Sorry for the bad English, I'm using google translator.
I'm having some problems with the graphical interface Enlightenment, eventually it freezes in what I could observe, every time I run Alt + F2 calling it constantly the problem happens.
I've updated to the latest version, removed all the ports and installed again, reinstalled the system from scratch and the problem happens, another detail I noticed is that only occurs when I'm using the proprietary Nvidia modules.
Follow the system information, what you need information is just request that I make available.
*** This bug has been marked as a duplicate of bug 219676 ***