I have 15" Early 09 MBP connected to a 24" ACD and i've just gotten my second graphics glitch in the space of 5/6 months. Should i be worried. A restart seems to solve the issue in both cases but i can't help but wonder if there's something else wrong. It seems to happen whilst i'm in Safari too.
Links to video of the issues can be found here and here
Links to video of the issues can be found here and here