Strange Background

Masters,

I have a strange background problem in my render. I put an HDRI map in the environment tab to be used as background of my model..At the start of rendering process everything looks fine, however, after two to three hours, the rendering started to show incorrect color in my background..The image below shows the incorrect color of the background.The upper left portion of the image is different from the upper right.What I have done wrong?? Is it memory problem? im using 64 bit core i3 with 4gig ram. Or is it because I checked clamp output in the vray color mapping rollout(my suspect).Please help po...

[img:84a3]http://www.cgpinoy.org/[/img]

might be because you have increase multiplier of HDRI. to me the background look good. you can also manipulate background if you save image with alpha channel.