Huh, the only thing that didn't work for me right away was the text size (it was HUGE). I had to run the
MAMEWAH Layout Designer.exe
and select the .lay file, then change the text.
Now, there is also an "image" option under the "background" menu. FYI you can also change color depth and refresh rate here.
Also, make sure your MAMEWAH/FILES/MAMEWAH.CFG has the
Layout Name = <your layout name> correctly set,
and that your layout file and background image are in
the MAMEWAH/LAYOUTS/<your layout name> directory
(ie you should have emu1.lay and emu1-main.jpg in this directory)
Just for kicks you might want to run the MAMEWAH setup program
(
http://www.mamewah-setup.co.uk/)and look under the "layout view" tab.