The biggest problem with sub Prime mortgages is that the US banks unloaded most of them to European banks who thought they were getting a great deal. It has caused a lot more financial problems in Europe and Asia than in the states.
Have a look at these articles ...
portland imc - 2007.11.24 - The Financial Tsunami: Sub-Prime Mortgage Debt is but the Tip of the Iceberg The Hindu Business Line : Sub-prime crisis: Europe trains guns on US