from PyQt4.QtGui import *
from i18n import _

class HistoryWidget(QTreeWidget):

    def __init__(self, parent=None):
        QTreeWidget.__init__(self, parent)
        self.setColumnCount(2)
        self.setHeaderLabels([_("Amount"), _("To / From"), _("When")])
        self.setIndentation(0)

    def empty(self):
        self.clear()

    def append(self, address, amount, date):
        if address is None:
          address = "Unknown"
        if amount is None: 
          amount = "Unknown"
        if date is None:
          date = "Unknown"
        item = QTreeWidgetItem([amount, address, date])
        self.insertTopLevelItem(0, item)


from PyQt4.QtGui import *
from i18n import _

class HistoryWidget(QTreeWidget):

    def __init__(self, parent=None):
        QTreeWidget.__init__(self, parent)
        self.setColumnCount(2)
        self.setHeaderLabels([_("Amount"), _("To / From"), _("When")])
        self.setIndentation(0)

    def empty(self):
        self.clear()

    def append(self, address, amount, date):
        item = QTreeWidgetItem([amount, address, date])
        self.insertTopLevelItem(0, item)


--- 
+++ 
@@ -13,6 +13,12 @@
         self.clear()
 
     def append(self, address, amount, date):
+        if address is None:
+          address = "Unknown"
+        if amount is None: 
+          amount = "Unknown"
+        if date is None:
+          date = "Unknown"
         item = QTreeWidgetItem([amount, address, date])
         self.insertTopLevelItem(0, item)
 
Fix for slush's problem, perhaps
