This looks like 3DSMax Bitmap node issue which has been widely discussed on the forums, where Bitmap node sometimes load textures with different gamma settings.
The easiest way to fix that is to convert all Bitmap nodes to VRayHDRI ones via Bitmap to VRayHDRI script that comes with V-Ray.
Related Thread: http://forums.chaosgroup.com/showthread.php?74602-pale-dark-DR-buckets&highlight=buckets