Delayed aircraft texture loading

High,for about two weeks, I am experiencing an annoying, delayed loading of aircraft textures. When flying with ** B-17 in 2D cockpit, for two or three minutes straight ahead and then looking outside to the left (keypad 4 command), I am seeing the left wing and engines without any texure placed on, and it takes , may be, half a second until aircraft textures become visible. I am quite certain that, I did a lot of flights before, with the same aircraft, and I have never looked at the uncoloured, aircraft model. Aircraft texure was already applied, whenever looking outside left or right. There was never any delay in applying the textures. Anything must have been changed in FS settings or eventually WinXP. Unfortunately I am absolutely clueless how to improve that problem. New installation of FS9, did not improve anything. Thank you for any help Bruno