Well, for one, Asus boards generally read higher than other mobo manufacturers. Also, why did you go with a Chrorb? Why not keep the stock HSF?
EDIT: I re-read the post, and I see now. You switched to Asus, temps were 120-140. Put on Chrorb, and temps are 118 now, but comp wont boot at speed it would before. Odd indeed. Maybe NBridge is overheating? Might wanna remove HSF from northbridge and apply some Arctic Silver... Other that, I'm at a loss. I'm sure some other people have more experience than I do.