Did you have the laptop in direct sunlight Is your mac book a thin? because thin laptops cannot release heat as well as a laptop that is thicker in width. You could try a cooling pad that connects to your usb port and has extra fans underneath increase ventilation. Also keep your laptop elevated by buying some elevation pads from ebay for a couple of bucks. THe better you can increase the airflow the better your pc will run at its full potential. Also try not to run anything cpu intensive while you DJ, the harder you push your machine the more heat!
mate, try downloading the official graphics driver from the manufactures website. Sometimes getting the drivers from nvidia can cause issues. Bios update is a good start too, but sounds like graphics to me.
i am an advanced dj now, but going back to basics and reading this info was a refresher. Your info was very accurate and i came up with one question that has been bugging me from day one. Does a more expensive mixer give you better sound quality and volume when playing the highest quality mp3 files or vinyl etc?
it could be various things! i have had no issue. Could be anything from your internet browser, internet connection type, laptop specs, viruses and so on. A little more information is required for this type of problem. Cheers!