[crash] Visual bug in game followed by crash

Since the patch every game I have played has had visual effects issues causing random shapes and colors to flash across the screen. (Most prevalent at the start of a match) The visual issues did die down a bit as the game progressed but would reappear whenever multiple abilities were triggered in the same area.

As I was playing 2 separate games with Syria the screen randomly went black and I would have to put my computer in sleep mode and wake the system back up to get out of that black screen and into my home computer screen. The first game this only happened once. The second game however had it occur twice with the second forcing me to actually power down my computer.

My current system is an IMac running Mountain Lion operating system. I have also had no other problems with the game on this system until after this patch.