I see where you're comin' from now... Hm... It's a toughy. If the artifacts are reallllly buggin' ya, go for it... But I, not necessarily you, don't like to spend money unless I HAVE to... Or really feel like it.
A 6800 shouldn't be putting of those kinds of temps, though. So, if you're still under warranty from the manufacturer or something... Try trading it out for another one.