Per-pixel spotlight problems

In my game, I finally was able to get per-pixel spotlights to work (by using projected textures), but for some reason all the spotlights in the game also have a reverse projection (opposite of the line-of-sight) as well as this ugly line of light that goes out perpendicular to every light on both sides. I was able to get rid of the reverse projection by keeping the 'y' coordinate of the projected texture positive in the vertex shader, but the ugly "line of light" (or lines) is still there. Here is a screenshot of what I am talking about: The spotlight is going off to the right, and you can see the ugly "lines of light" going off to the end of the map and coming back towards you. Does anyone know how to get rid of this?