2 layer bump terrain dynamic lighting?

Hiya
I’ve been playing around with the 2 layerr bumped shader and its great, but for some reason it only seems to be affected by 1 light source. Is this correct. I plan to have direct lighting from the moon (this works) but I also want the player to use a torch. The light from the torch does not seem to show on this shader. Is there any way around this?
thanks in advance.
Gaz

after playing around a bit more, it seems that I can use additional direct and point lights, but not a spot light (which is what i would prefer to use for a torch). Any ideas?