CTD when change screen resolution

Hi, I need advice on this issue.I have recently added a second LCD monitor. This is one is 22 inches and the first one 19 inches.I always used at 1280 x 1024 on the 19". When I added the new 22" monitor I set 1680 x 1050 resolution, and keeped the 1280 x 1024 on the old one (19").With this configuration the FSX start and run on the new monitor. Once I select the airplane and the airport it begin to load. When the scenery and plane must appear a the screen I get the CTD. I don