Anisotropic texturing not working and making textures blurry

Since the question was bumped again, I just want to make something clear: Anisotropic filtering is just mipmapping on steroids. It's still just mipmapping but it has additional mipmaps for cases when the surface is viewed at a very narrow angle. In those cases it will pick a mip map variant that has a high horizontal resolution but a small vertical (the direction that is actually squished). However as the distance increases and the size of the texture on screen gets smaller, it will pick smaller and smaller mipmap levels. Having very sharp / high contrast one pixel borders in textures will always cause issues. Sooner or later that single pixel border line is smaller than an actual pixel on screen. Without mipmapping you would get Aliasing which would cause Moiré patterns. So when you move your camera around you would get some flickering in the distance because sometimes the screen pixel would show the border color and sometimes it doesn't (so the line is essentially between two screen pixels). The point of mipmapping is to downsample the texture when it is shown smaller on screen to get a consistent image quality. However that always means you get some blur.

So this issues is amplified by the a specific content of your texture. Having such thin and sharp lines is just not going to work really well.