Hi, SDL has gone thru quite a bit of changes lately, with the current version being 2.541. Your program seems to use an older version, as SDL::App is from version SDL_Perl-v2.2.6 from 2009. Maybe someone knows the proper code usage for you, but you might want to upgrade to the latest 2012 version, and rewrite. I'm not inclined to install an older SDL version just to test your code.