diff --git a/src/cutecoin/core/net/node.py b/src/cutecoin/core/net/node.py
index 1fd819567498959b38b9d5ed86722d69bdb7ce82..6ed23a0e504717eef72053c9058a81b674d72692 100644
--- a/src/cutecoin/core/net/node.py
+++ b/src/cutecoin/core/net/node.py
@@ -34,13 +34,7 @@ class Node(QObject):
 
     def __init__(self, currency, endpoints, pubkey, block, state):
         '''
-        Constructor of a node
-
-        :param str currency: The currency name of this node community
-        :param list endpoints: Endpoints ucoinpy objects
-        :param str pubkey: The node pubkey
-        :param int block: The node last current block
-        :param state: The state of the node
+        Constructor
         '''
         super().__init__()
         self._endpoints = endpoints
@@ -117,7 +111,7 @@ class Node(QObject):
         return self._pubkey
 
     @property
-    def endpoint(self):
+    def endpoint(self) -> BMAEndpoint:
         return next((e for e in self._endpoints if type(e) is BMAEndpoint))
 
     @property
@@ -219,3 +213,7 @@ class Node(QObject):
                     time.sleep(interval)
         except RequestException as e:
             self._state = Node.OFFLINE
+
+    def __str__(self):
+        return ','.join([str(self.pubkey), str(self.endpoint.server), str(self.endpoint.port), str(self.block),
+                         str(self.currency), str(self.state), str(self.neighbours)])
diff --git a/src/cutecoin/gui/currency_tab.py b/src/cutecoin/gui/currency_tab.py
index d91e9a8b7ae247e317b1af61edaa68f2f0d9ce13..4ccf8b02566ce9806b889f2fefdadc5ebdf21503 100644
--- a/src/cutecoin/gui/currency_tab.py
+++ b/src/cutecoin/gui/currency_tab.py
@@ -5,6 +5,7 @@ Created on 2 févr. 2014
 '''
 
 import time
+import logging
 from PyQt5.QtWidgets import QWidget, QMenu, QAction, QApplication, \
                             QMessageBox, QDialog, QAbstractItemView, QHeaderView
 from PyQt5.QtCore import QModelIndex, Qt, pyqtSlot, \
@@ -145,6 +146,13 @@ class CurrencyTabWidget(QWidget, Ui_CurrencyTabWidget):
                                      QIcon(':/icons/informations_icon'),
                                     "Informations")
 
+            # fix bug refresh_nodes launch on destroyed NetworkTabWidget
+            logging.debug('Disconnect community.network.nodes_changed')
+            try:
+                self.community.network.nodes_changed.disconnect()
+            except TypeError:
+                logging.debug('No signals on community.network.nodes_changed')
+
             self.tab_network = NetworkTabWidget(self.community)
             self.tabs_account.addTab(self.tab_network,
                                      QIcon(":/icons/network_icon"),
diff --git a/src/cutecoin/models/network.py b/src/cutecoin/models/network.py
index 528e1632ac06ea6c5f2ee2995618a35add9b7874..f44a7735e3ea146d5d279a30d5412758979dcd59 100644
--- a/src/cutecoin/models/network.py
+++ b/src/cutecoin/models/network.py
@@ -94,7 +94,12 @@ class NetworkTableModel(QAbstractTableModel):
 
         return self.column_types[section]
 
-    def data_node(self, node):
+    def data_node(self, node: Node) -> tuple:
+        """
+        Return node data tuple
+        :param ..core.net.node.Node node: Network node
+        :return:
+        """
         try:
             person = Person.lookup(node.pubkey, self.community)
             uid = person.name
@@ -112,7 +117,7 @@ class NetworkTableModel(QAbstractTableModel):
             address = node.endpoint.ipv6
         port = node.endpoint.port
 
-        return (node.pubkey, is_member, uid, address, port, node.block)
+        return node.pubkey, is_member, uid, address, port, node.block
 
     def data(self, index, role):
         row = index.row()