I had a version of this problem myself. My problem was that the video card I was running AH off of was not powerful enough. No matter what graphics settings I changed, even after lowering every possible option to the lowest setting, the problem would not go away. I have a laptop, which has two video cards apparently. Default had it running off the "battery saver" option, which made AH run off of the lower powered HP Internal graphics card. Once I switched it over to "High Performance", and it started running on the higher powered AMD Radeon card, this problem completley went away. My guess is your onboard card just isn't powerful enough.