MacBook Pro 15 inch Mid-2010 keeps randomly restarting
So, I got this Macbook back in August of 2010, and this random restart problem just started occuring after I updated to Mountain Lion. It usually occurs when I open up heavy usage applications, such as Photoshop, iMovie, iPhoto, FaceTime,etc. When I just solely decide to turn on my MacBook to just use Safari and iTunes, it never restarts, or it will once in a blue moon. Also read a page Apple posted about MacBook Pro 15 inch Mid-2010's having problems and that they would fix it free of charge, but I'm not sure if that relates to my problem? --link here --> http://support.apple.com/kb/ts4088
I tried resetting the SMC, and NVRAM/PRAM. Even verfied disk permissions and repaired on Disk Utility, nothing changed.
Could anyone help?
MacBook Pro (15-inch Mid 2010), OS X Mountain Lion (10.8.3)