Hrm I think I know this, but my memory is "elusive" on this part.
If this plane is set in the camera attributes you can set the "thingy" in the attributes to "none".
Else if the image is on a plane, you can hide the object or go into the attribute editor for the object in question and set render attribute; "Visible" unchecked.
Maybe somebody else can verify this also.
I do not support Bush! Nor Saddam! Long live UN!