To use an image for the heading, put its name and the alt text for it in the define as the examples show:
PHP Code:
define ('CAT_BOX_HEADING_7','1|0|g_neonati.gif|Giocattoli neonati'); 
Replace g_neonati.gif|Giocattoli neonati with the filename and alt text you want.

If you want to use an image behind the existing text, leave the define as is and add the image as a background-image in .catBoxHeading1 {}. You can find my e-mail in the readme file - thanks:)