Distant Light can not pass wall on IRay render?

Hi guys,

I try to do some lighting with Distant Light on http://www.daz3d.com/level-19 and see a result:
Distant Light pass wall on View, but when I do Iray render, it is completely dark. I move the Light Direction to an open wall then it display.
I do not see an option to move the Distant Light to nearer so that it can over the wall also.

Do you have any idea to make it work for a Distant Light through the wall?

Thank you