Well I have never worked on a dual core but I you don’t see it their I really don’t think you have a dual core then… when you say lock up JUST et or everything? Maybe the processor is over heating? (seen it before) (
http://www.almico.com/speedfan.php will tell you the temps of all the sensors you have on the comp) does the FULL comp lock like need to pull power and restart or does closing ET fix it? And ONLY pro right? Norm et and shrubet etc are fine?