Mach: The "W1551" warning is a bug of all Geforce 6xxx and 7xxx drivers. It's fixed from 8xxx on. This is an issue I've recently learned. There is no real fix for your GeForce card, but the error message will be suppressed in the next update and the shader will then work again.

Vlau: For bumpmapping you need to create a normal map for your model. You'll find basic information about bumpmapping in the shader workshops. Use the shader viewer to see how fx_bump looks.