how did you map this fella?
either you have overlapping uv’s or you are trying to texture auv/guv tiles with a texture that is larger than the texture size you used to create the uv’s.
if you used default zb. that is i believe auvtiles created at 1024x1024 and if you use a texture later at 2048x2048 you now have two pixels vying for 1 pixel space.
create a texture in the size you plan to use for textures,
go to first subd level, go to tools>texture and hit guvtiles
this will give you the proper uv’s to match your texture.
if you mapped it else where go to tool>texture and use the check uv button if you see red you have overlapping uv’s and that will cause you funky results.
hope something there is the answer