Every time I have experienced an update and upgrade I have run into big trouble. The screen is freezing and greying out, everything slows down or stops working after a while, Skype won't connect, or if it does, the sound is a mess. This is what happened lastly when I upgraded to 12.10. Lost Unity, Cairo-dock did not start, Skype not working, pressing shut down made the computer freeze completely. Every problem in the book was there. Now I finally found out that the solution that made Skype working...
