standard or photometric ligts don't read in mr environment

[brandusabularca]

I'm rendering an image with mental ray materials and a daylight system (mr sky and my sun.) The image looks great just using the natural light and very realistic. However, in the areas where natural light doesn't reach I need to place articficial lights. I tried both the standard and the photometric lights and none of them renders no matter how much I adjust intensity or multiplier. It's as if those lights don't read at all. I've rendered with mental ray before using global illumination and final gathering and didn't have this problem.
Do you know why artificial lights wouldn't show?
Thanks a lot.

[Steve_Bennett]

You shouldn't need additional artificial lights. Try turning on Global Illumination, Final Gather and adjusting their settings appropriately.

[brandusabularca]

i don't need in that particular view of the model but for example, i'm rendering now an image of the bathroom in the same house (model) that just has a skylight. it is too dark without artificial lights and i tried to add some but they still don't read. i tried to change the final gather and global illumination parameters but nothing i do makes the artificial lights read.