wordpress is_page() problem

You probably want to drop the conditional during init. You are just registering the script here, not enqueueing it. Once registered, you should be able to call the script later in the action sequence. Please try something like this:

function myplugin_css() {
    if ( is_page( 'myinfopage' ) ) {
        wp_enqueue_script( 'RGraph' );
    }
}
add_action( 'wp_print_scripts', 'myplugin_css' );