It can be heat or a driver issue. When I see this I often find that a thorough cleaning down to the heatsinks is best for older laptops. We have a note about cleaning with pictures in this forum's sticky post.
Next? Your post reveals there was a driver bug and it appears you never tasked the maker to fix it. At over 2 years that opportunity is now gone so when you have a backup of your system you could try other video driver versions or reload the OS.
I have a 2.5 years old Sony Vaio. About six months ago the screen started going fuzzy at times. During that period I was not shutting down my laptop, but I was having it sleep or hibernate. When I stopped that, the problem stopped.
Now it has started doing the same thing again, eventhough I shut it down.
I have recently installed Ubuntu Linux along with my Windows system but I don't think this has anything to do with this.
Anyone have any ideas?