Just thought I would update this post in case anyone reads it. I finally gave up on trying to troubleshoot and fix this problem myself. I had a repair technician come out and after a complete physical of the furnace, gave it a clean bill of health, HOWEVER, He found a rather large dead bird in the flue. He also pointed out that the chimney cover was missing (probably due to one of the rather large storms that came through our area this year. Lesson learned: make sure that you pay attention to the chimney as well as the roof and siding after a large storm passes through and make sure that the chimney has the proper shroud. Also NEVER assume that the furnace has a problem until the whole system is checked out!!
Hope this helps someone else in the future.