Lightbox Plus Colorbox WHITE line when image opens

Hi,

I am using Lightbox Plus Colorbox version 2.72, and wordpress 4.2.2. This plugging has been working great except for a thin WHITE line that appears across the image when it open in the lightbox. I have not idea how to get rid of the thin white line, and I tried playing with the settings options and even reseting everything but not luck at all. Since this is my first time creating a website I am using a maintenance mode until the website is ready to be public.

can anyone shine any light into this issue, any suggestions are welcome.

thanks in advance.