Try a new level without the shader and see if stencils show up, that might give you a comparative and from there you can determine what the cause may be for the current problems
Another factor to check out, is the model closed off? Important as a model with big holes will either display strange artifacts.
Last edited by KiwiBoy; 05/28/0918:37.
Use the 'manual' Luke, the manual is your friend. 'Self reminder'