Darn, there's a bug in the bugfix ...
The correct code is;
//Minify
if (class_exists('Minify_CSS_Compressor')) {
// legacy
$tmp_code = trim(Minify_CSS_Compressor::process($code));
} else if(class_exists('CSSmin')) {
$cssmin = new CSSmin();
if (method_exists($cssmin,"run")) {
$tmp_code = trim($cssmin->run($code));
}
}sorry about that :-)