CTD after change the time setting in some airports

Hello to all. I generally run the FSX smoothly. But after some addons, sp1 and sp2 installed, I encounter the CTD problem after changing the time setting in some airports.I had tried some busy airports (addons and defaults) around the world. I found out paris and london's airports causing the problem. I do have addons in london, but not in paris. I am not sure whether is software or hardware's problem. Before I am going any further, I would like to ask any advice. Any Help will be highly appreciated!I am using Dell Inspiron 530s, dual core 2, E6550 2.33GHz, ATi Radeon x1300, 3GB physical memory, DirectX 9.0c, 80GB free space for FSX.