I just copied my first background file over and got it to work no porblem after figuring out the right naming
Make sure you have the most up to date versions of SMS and the image generator (both downloadable from http://home.casema.nl/eugene_plotnikov/ )
Create a skin using your desired image file (800 x 600 or less) and name it SMS.smi (EXACTLY) and copy it to MC0:\SMS\ (if in slot 1) and enable use background and make sure to save settings before you close SMS or you will have to re-enable it next time you start up.
If your still having trouble let me know.
"My logical data analysis sector indicates that would be highly unlikely. And my bullshit meter agrees."
Sheila, Red VS Blue