Was there a drop in performance ? The passes go so slowly, like 10 times compared to simple region.
Try to turn adaptivity off and see if there’s difference.
And try to make a small 3ds Max Render region around your selection. =) It should be help a little.
Actually I thought of that :- D Does that make it work… ?
Sometimes it does, sometimes not 
The bug is very annoying.
I was worried, that since I don’t know how this thing works internally, that it could affect the light in some way (combining both two features).
But was it like this in 1.3 ?
I don’t use it often, so I am not sure…