Having some real BIG problems with a/c textures!!

Hi all, I'm having big problems with a lot of my a/c for FS2002, the textures on all my default a/c and the AI default a/c are flickering they are then getting covered up by funny rainbow coloured textures. When i zoom right in they disappear it seems as if they are masking the proper textures when i zoom out. If anyone could help me i can send you an email with a BMP image to show you because i can't post on the screenshot page for some reason. drop me your email address and i'll send the pic along.Many thanks,Simon