Why is there a Mac version if it doesn't work?
You can package decals for Windows on Mac by using a different zip compression program (other than the default one, where you just right click and select 'Archive'). It's best to have just one download link.
http://www.macupdate.com/info.php/id/19139
Crap, now I'm out of a job :P
Blyde, dont you have some fanceh PhotoShop?