diff --git a/doc/Build.txt b/doc/Build.txt
index 782c057ea9caa6354781752550f4ed02991733a4..e37925a2938e694f49684fffc80cdc1a7325c773 100644
--- a/doc/Build.txt
+++ b/doc/Build.txt
@@ -27,6 +27,14 @@ sudo make install
 You can replace `--prefix=/usr` by whatever prefix you like. Make sure to
 also change this value in the next steps.
 
+Run:
+
+--------------------------------------
+./configure --prefix=/usr --with-debug
+--------------------------------------
+
+to enable debug mode.
+
 NOTE: If you have `colorgcc`, configure will *fail* on `libeXpat`. Issue an `unset CC` and `unset CXX` to build the dbus bindings.
 
 
diff --git a/src/iaxvoiplink.cpp b/src/iaxvoiplink.cpp
index fbac29a1de7b380a551e92f4e04e0cf4acb8bc77..34955326589b6a31b0e40d43ca2e1a61a5b1ccf4 100644
--- a/src/iaxvoiplink.cpp
+++ b/src/iaxvoiplink.cpp
@@ -223,7 +223,7 @@ IAXVoIPLink::getEvent()
     sendRegister();
   }
 
-  // thread wait 5 millisecond
+  // thread wait 3 millisecond
   _evThread->sleep(3);
 }
 
@@ -440,16 +440,17 @@ IAXVoIPLink::sendRegister()
 bool
 IAXVoIPLink::sendUnregister()
 {
+  _mutexIAX.enterMutex();
   if (_regSession) {
     /** @todo Should send a REGREL in sendUnregister()... */
 
-    _mutexIAX.enterMutex();
     //iax_send_regrel(); doesn't exist yet :)
     iax_destroy(_regSession);
-    _mutexIAX.leaveMutex();
 
     _regSession = NULL;
   }
+  _mutexIAX.leaveMutex();
+
   _nextRefreshStamp = 0;
 
   setRegistrationState(Unregistered);
@@ -736,7 +737,7 @@ IAXVoIPLink::iaxHandleCallEvent(iax_event* event, IAXCall* call)
     break;
     
   default:
-    _debug("Unknown event type: %d\n", event->etype);
+    _debug("Unknown event type (in call event): %d\n", event->etype);
     
   }
 }
@@ -948,7 +949,7 @@ IAXVoIPLink::iaxHandlePrecallEvent(iax_event* event)
     break;
     
   default:
-    _debug("Unknown event type: %d\n", event->etype);
+    _debug("Unknown event type (in precall): %d\n", event->etype);
   }
   
 }
diff --git a/src/sipvoiplink.h b/src/sipvoiplink.h
index 215e13ee00c9936e1a33c00ec12be4e38a314421..d49a700a09fcbd907ee48293fb0372cbf7b2c723 100644
--- a/src/sipvoiplink.h
+++ b/src/sipvoiplink.h
@@ -1,7 +1,7 @@
 /*
  *  Copyright (C) 2004-2006 Savoir-Faire Linux inc.
  *  Author: Yan Morin <yan.morin@savoirfairelinux.com>
- *  Author : Laurielle Lea <laurielle.lea@savoirfairelinux.com>
+ *  Author: Laurielle Lea <laurielle.lea@savoirfairelinux.com>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by