Blender Lights bug?

the following has happened to me several times:

in a scene where the lights are all behaving correctly (the intensity I want) I add another light, say, to gain shadows or light some part specifically.

test render.

the result is like as if all of the lights intensities were cranked up 10 times, a very over-exposed, blasted-out render.

you’d think dialing down on the new light, or deleting it from the scene would help, but it doesn’t. render still blasted out.

then, I spend best part of an hour render, turn one light off, render turn another off, render…

Adding a lamp to a scene is a function of blender, and shouldn’t wreck the whole scenes’ lighting.

any thoughts on this?

I don’t know that I could re-create it but have heard others suffering the same problem.

Thanks!

Send a .blend file, say which renderer (Cycles, Internal, Yafaray, Luxrender), which build etc.

to where? this file is a mite large…I suppose I’d need to pack it first?

Even better, find steps to reproduce the problem. I’ve had issues with MIS in cycles causing certain lights to lose intensity, but i’ve never experienced them gaining intensity.

Are you in textured mode? Because it normally looks over-exposed in solid view mode.