Hi Brujito, since I mentioned MGIC in my response below I also wanted to make you aware that since we are talking about insurance, and therefore risk, guidelines can change at any time.
Case in point:
Announced yesterday, and going into effect March 8th, MGIC will make pricing and criteria changes in response to losing market share to FHA loans and also to keep their #1 position among MI companies. The new pricing scale will use borrowers' credit scores to set premium rates with lower prices for borrowers with the best credit history and higher premiums for those with worse scores. MGIC hopes this will not only increase revenue but will also shift their business toward borrowers with FICO's above 720. For all markets and origination sources, MGIC will require a minimum of 3 credit tradelines evaluated for 12 months. Without this, the loan must meet MGIC's nontraditional credit guidelines.