Vertex ordering?

I have a model that is showing up fine, but the texture on it is all over the place. I have the texture loaded, and the texture coordinates are correct. I have checked them by having my program draw dots on the texture where the coordinates are and saving the bitmap back out. All is fine. My question is, does vertex ordering (clockwise or couterclockwise) make a difference to texture mapping? I assumed that if the vertices were mapped to the right texture coordinates, all would be fine regardless of the order of vertices. As I said, the model is drawing perfectly. It''s just the texture mapping that is hooped.