Phantom Light???

[Intrinsia]

I have come across an odd issue that I have never seen before. I was handed a scene to render and found it was taking a while to render. So through debugging I deleted all lights, turned off GI, used an override material, and for some reason my scene still renders as if it has a light(s) in it. If I turn off "Lights" in the global overrides then it renders quickly. But if I render it normally with the override material and "Light" ticked on it calculates and renders lights/shadows. Has anyone else come across this before?

I'm stumped! :P

3dsmax 2011 / Vray 2.10.01

Edit: I think it may have something to do with certain objects being assigned light emitting materials. Does Vray create an attribute that might cause the object to emit light even though a material override has been set?