diff --git a/gui/chromeTabs.py b/gui/chromeTabs.py
index 09bbcfb0a..0c7819f18 100644
--- a/gui/chromeTabs.py
+++ b/gui/chromeTabs.py
@@ -102,7 +102,7 @@ class PFNotebook(wx.Panel):
         return self.pages[i]
 
     def SetPage(self, i, page):
-        if i >= len(self.pages):
+        if i >= len(self.pages) or i is None or page is None:
             return
 
         oldPage = self.pages[i]
@@ -123,7 +123,7 @@ class PFNotebook(wx.Panel):
         return self.activePage
 
     def GetPageIndex(self, page):
-        return self.pages.index(page)
+        return self.pages.index(page) if page in self.pages else None
 
     def GetSelection(self):
         return self.GetPageIndex(self.activePage)
diff --git a/gui/fittingView.py b/gui/fittingView.py
index c3c1a0e63..f00d74560 100644
--- a/gui/fittingView.py
+++ b/gui/fittingView.py
@@ -100,6 +100,9 @@ class FittingView(d.Display):
         self.Bind(wx.EVT_RIGHT_DOWN, self.click)
         self.parent.Bind(gui.chromeTabs.EVT_NOTEBOOK_PAGE_CHANGED, self.pageChanged)
 
+    def Destroy(self):
+        self.parent.Unbind(gui.chromeTabs.EVT_NOTEBOOK_PAGE_CHANGED, handler=self.pageChanged)
+
     def pageChanged(self, event):
         if self.parent.IsActive(self):
             fitID = self.getActiveFit()