I'd say thats too hot, might be causing the artifacts too. Hows your incase air-flow? Try opening your side panel to see if that helps, that card doesnt expel air hot out so its possible it could just be self heating itself if you dont have a constant stream of new cooler air.
That's very hot for an idle temp for a modern card. I've never had a video card idle hotter than 50C and that was an 8800 GTX that didn't have the ability to downclock while in 2D mode in a case with bad ventilation. I'd return it.