Hmm, since I don't have it, then you are saying that something is wrong? I don't think so.It is normal effect, and if you didn't have it, something would be wrong.
The ray of light is extended from the taskbar isn't it?
Attachment 1 is of the normal view, and attachment 2 is with show desktop, and you can see where the ray of light starts.
So looks like this is normal.