NEW YORK--(BUSINESS WIRE)--Fitch Ratings has upgraded one and affirmed 17 classes of Credit Suisse First Boston Mortgage Securities Corp. series 2005-C5, commercial mortgage pass-through certificates. A detailed list of rating actions follows at the end of this press release. KEY RATING DRIVERS The upgrade and affirmations are due to stable performance and continued pay down since the last rating action. Fitch modeled losses of 10.3% of the remaining pool; expected losses on the original pool b