how to create cube map using vray?

Greeting people... Currently im working on an interior scene... im trying to create a cube map for reflections of the objects inside.... i followed the tutorial here... http://wiki.polycount.com/CubeMap and the maps that i got are all over exposed... im not sure how to make them render in proper way... im using gamma 2.2, vrayphysicalcamera, vraysun, and vraysky for my rendering.... is it because the method i followed are never meant for vrayphysicalcamera, vraysun and vraysky? is there any other way for me to create a proper cube map by using vray???