I had a similar problem except mine got so bad that it was causing the computer to crash.
I actually did the same as the link below and took my video card out and baked it at 195C (383F) for 10 minutes. I then let it cool for 2 hours and tested it out. My video card works perfect now and the laptop no longer crashes. From what I have read on multiple sites the cards can get micro-fractures in the solder over time and baking the card melts the solder just enough to repair itself.
I'm not sure if you should risk it yet but if the card it not working anyway then it cant really hurt to cook it.
Here is the post I read but there is a lot out there on google if you search for "Video card oven"
Well now I just noticed your post was really old.