Thanks for your comments,
personally, I was used to lock ONLY the white background for all my files, and Istock (and other stock sites) never had problems with this. I considered the white background as not being a part of the illustration, like the white paper sheet, and not having to be edited, or moved. And that makes it easier for editing objects without moving the background. But that will change for now... I don't want to spend more time for re-uploading to veer.