I have done a fresh install of fsx followed by sp1 and finally fsx:accel. Every works fine with the default aircraft. I downloaded some new aircrafts from flightsim website. No matter which addon aircraft i load there are no textures/liveries on it. It is plain white. If i select any of the default aircraft of fsx this problem doesnt crop up. The problem is only with the addon aircrafts.
Next I went into the Simobjects/aircraft directory where all the airplanes are stored. In the textures directory of each addon aircraft the textures are in BMP format. But the textures for the default aircraft are not in BMP format (DDS if i am not mistaken). I guess fsx:accel does this to all the aircraft that already exist. Never had problems earlier when I used these addons with just fsx. In order to smoothly install fsx:accel i uninstalled fsx and all addons and then re-installed step-by-step. So i think I need some kinda conversion tool to convert these textures to the new format. Any help to solve this issue would be appreciated.