I have modified the lighting in cell cragwallowslope01 as follows

1. reduced the Ambient, Fog Near, Fog Far, Directional, and Directional Ambient RGB values to 0,0,0
2. set a number of omni lights to "initially disabled"
3. reduced the radius and brightness of a number of light objects
4. changed the emittance for certain FXMistLow objects to NONE.

In the Render Window, it looks appropriate; however when I go ingame and COC cragwallowslope01 from the start menu, the lighting is reverted to the vanilla version of the cell. If I walk forward from the COC marker and take the right tunnel leading to a larger chamber, when I step into the the larger chamber, suddenly the lighting transitions to the correct (significantly darker) modded version. If I step backwards, the lighting transitions back to vanilla.

Is this a bug, or is there something I am doing wrong. I haven't observed this "transitioning" effect in any other modified vanilla cell I've worked on previously.

If anyone cares to help me test this, you may download the plugin file http://www.4shared.com/file/qPKYjP79/CragwallowSlope01TEST.html?

Lighting can be set with roombounds to values other than those in the cell parameters. I believe the area that is lit correctly is not in a roombound, or not in a roombound that alters the lighting. To correct this effect, remove all the lighting changes that roombounds do, or remove the roombounds (Not recommended).

Thanks very much - figured out the problem Alex!

In my Show/Hide menu I had roombounds set to invisible!