Small bug in content-type properties, thanks Ryan (hairball57) for reporting.

class/mime/Rfc822Header.class.php

@@ -524,7 +524,7 @@ class Rfc822Header {
         $props = '';
         if ($pos > 0) {
            $type = trim(substr($value, 0, $pos));
-           $props = trim(substr($type, $pos+1));
+           $props = trim(substr($value, $pos+1));
         } else {
            $type = $value;
         }