Strange Rendering Errors (Shading)

[Krallis]

When I plug my normal map into the "phong" node in my shading network it looks fine when hit with direct light, however there appears to be some strange errors when there's no light hitting it. Like big dark splotches that seem to be caused by the normal map. However the normal map itself is pretty good with no glaring errors on it.

Now when I plug the normal map directly into the "main" node in the network these strange splotches disappear, which would be ideal. However the shader doesn't seem to react to lights anymore. At least not any that I've placed.

Anyone know whats up?

(using Softimage XSI 2012)