The actual problem is this: ERROR: Shadow mapping is not supported by the current hardware!
A real GeForce4 can do it (anything up from a GF3 supports it), but you are using a GeForce4MX, which is basically a GF2. There's nothing i can do about it. The MX doesn't have the hardware caps to do it. The null pointer shouldn't happen anyway in this case. I'll fix this.
Edit: If you want to use this feature, get something from a GF3 upwards, i.e. a GF that supports at least pixel shader 1.1. Don't get an ATI unless it's a real new one, because older ATIs have some problems with depth textures.