Some insightful comments on the US Sub-prime problem, from the incredibly rational blog, Econbrowser. 

But, as Felix Salmon observed, if anything the opposite appears to be the case: the states that are now experiencing the highest mortgage delinquency rates are the ones where the previous real estate appreciation had been the most modest

Source: Econbrowser: Bubble, bubble, toil, and trouble

I’d go further and note that this analysis suggests that the problems lie in the poorer states, or at least those states that have a relatively high representation of lower income.