the new toolkit.exe worked a treat and allowed me to make a full size profile
of 3840x1024, where before it would not allow me to enter 3840, so excellent work there.
i increased the profiles window size gradually and the background appeared as you would expect, so far so good all the way out to the full 3840x1024.
getting this sorted has created another issue:
the mesurement tapes in the top left hand corner of the profile skin showing the x and y coordinates stop around 20" along the horizontal and similarly around 8 for the vertical, i cannot see the far right and bottom areas of the profile skin, eg: just like editing a 19" profile on a 15" monitor.
where the viewable area is far smaller than the skin of the profile.
if possible a way to scroll around as you do a web page or in paint, in order to view the entire profile as the editor takes up some of the viewable area.
another option might be like grabbing a PDF in acrobat and pulling the document around the page.
hope my feedback helps, and sorry to create more work for you.