Vray lights issue Maya

Hi, all.

I have been trying to figure this out but didn't find out why.
Some vray lights in my scene showed up the shapes after I
started adding environment fog. In the image, you can see
from top right and top left where there are some square shapes
which are from the lights. The "invisible" check box is checked
already and I also played around the attribute spread sheet
but wasn't able to sort this out...any idea? Thank you.