Siver texture for the AI plane or mine

Hi There,I have been seeing like a silver texture on my AI plane , and some times with my own aircraft, when I change Aircraft.All my texture are gone, and it becomes to a shiny silver texture.I have an Nvidia 8800GTS 512MB and the driver is the latest 175.19.I am running XP 32Bit.I use Nhancer .Any idea why, and how can I fix this.Thanks