diff -r 226fe5065cf2 -r b13ef712a2d7 master/fsm_slave.c
--- a/master/fsm_slave.c	Tue Sep 18 14:18:30 2007 +0000
+++ b/master/fsm_slave.c	Tue Sep 18 14:19:21 2007 +0000
@@ -685,6 +685,9 @@
 
     if (!slave->sii_mailbox_protocols || slave->sii_sync_count < 2) {
         // no mailbox sync managers to be configured
+        if (master->debug_level)
+            EC_DBG("Slave %i does not support mailbox communication.\n",
+                    slave->ring_position);
         ec_fsm_slave_conf_enter_preop(fsm);
         return;
     }