C++ :: Shadow Mapping Using DirectX

I have a problem with implementing Shadow Mapping into a project I am working on. I am very much new to shaders and I have been given a Shadow Mapping shader to implement and understand. I have mostly got my head round the concept and the code but I can't figure out why its not working.

As I understand it the main steps to follow are;

1) Render the scene from the POV of the light - this is done in ShadowMap::SetUpDepthRender where the view and projection matrices are passed to the shader.

2) Render all objects in the scene - this creates a shadowmap (depth map) via the shader.

3) Reset the view and projection matrices to that of the camera - done in ShadowMap::SetUpSceneRender.

4) Render the scene objects once more appling the depth map to them via the second pass of the shader.

The problem Im having is that I have a stripe of light running diagonally across the screen. It passes through the point of the spotlight that I am mapping for. I believe this is the shadowmap being applied to the scene however I could be wrong?

Below is the code in the ShadowMap class used for setting the fx file.

LPDIRECT3DSURFACE9 oldDepthSurface = NULL;
LPDIRECT3DSURFACE9 oldRenderTarget = NULL;
ShadowMap::ShadowMap(void) {
//Create our Light
Vector3D lightPosition(20.0f, 2.9f, 10.0f);
Vector3D lightDirection;

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