Comment 26 for bug 1424491

By running "sudo apt-get install libcheese*" you are basically reverting the mesa updates of 14.0.4.2. It'll remove all the new packages and give you the graphic stack compared to before installing the LTS enabled stack. Hence you can install fglrx again.
You'll still have the new Utopic kernel though. I'm not sure if that's a good or bad thing. I can imagine some incompatibility issues without the new mesa stack, but if it works for you for the time being...