Problem with OpenGL Textures+Fog

Hi,

I am currently writing a OpenGL-Programm to visualise railroad tracks and I have a problem with using textures and fog in the same picture:

As long as the fog is turned off, everything works fine, but when I turn it on, the texture map coordinates aren't clipped correctly at the borders of the picture. The triangles in the middle are textured correctly, but the ones that have to be clipped aren't textured at all, or the texture looks really weird.

If someone had the same problem and/or knows a solution, please let me know.

Thanks