http://lifewithushare.blogspot.fr/2008/01/simultaneous-streaming-to-multiple.html

--- upnp/src/inc/config.h.orig	Fri Nov  2 15:18:39 2012
+++ upnp/src/inc/config.h	Fri Nov  2 15:18:54 2012
@@ -90,7 +90,7 @@
  *
  * @{
  */
-#define MIN_THREADS 2 
+#define MIN_THREADS 6
 /* @} */