Thanks for the reply Conrad but that still does not do what I'm looking for.
I have checked the 'do not stretch logo' box but this is still only giving me a small area of the window for the logo. What I would like is to have the entire window, including the text area when that the field is left blank, and the areas to the left and right of the part where the logo sits to be usable for putting a graphic onto.
No matter what size image I try it only ever lets have around half the height of the window for the logo image and it seems to scale the width down in proportion to the height.
Also, it would be nice if this cannot be achieved to be able to change the font used for the text field, is it possible the use html to format the text field?
Here is a picture of what result I'm getting with a test image at the size of 1000 x 1000 px.