I just played the wmv without PPT and I saw that the white
background is gray.

The original video is a .mov and the background is white.
I imported it in Sorenson Squeeze do make a .wmv. and the background
turns to gray.

So, do you know which type of codec I need?
In sorenson squeee, I used wm video v9.

Or maybe it's not the good compression?

Thanks for your help....