Comment 2 for bug 63046

can you boot in safe mode (press escape at the Grub screen). Once you are in there, you want to type

sudo dpkg-reconfigure xserver-xorg

go through and answer the questions, defaults on most of these will be good. You will come to the section about your monitor. You will need to locate the horizontal and vertical refresh rates if you can, and type them in the correct area. There are times, especially with laptops, and the newer ones as well, where the refresh rates become confused and out of synch. Also if you can, get a copy of /var/log/Xorg.0.log and post it here as well. Thanks guys!