Lucky you, so to speak. Back in the day I had the same one, but it would pass their diagnostics, so they wouldn't repair it, though I could literally make it crash in front of the Genius Bar techs reliably and repeatedly (essentially the same way, by trying to do anything that hit the GPU a certain way - websites, Photoshop). "Sorry, our diagnostic tool says it's not the GPU". At one point I even demanded they do a completely fresh install of the OS. On first login, I fire up Safari, go to a certain site, crash. Restart, go to a different site, crash. "Sorry."