I think your code is pretty messy, to start with, making it harder to work with. Take a look at some of my code, because I am sure it will help you.

main.py:
Qt Code: 
  1. # Version: Traipse 'Pious-Paladin'
  2. #   $Id: main.py,v Traipse 'Pious-Paladin' prof.ebral Exp $
  3. #
  4. # Description: This is the main entry point of the oprg application
  5.  
  6. from PyQt4 import QtCore, QtGui
  7. from os import sep
  8.  
  9. from map_engine.map_dock import MapDock
  10. from chat_engine.chat_dock import ChatDock
  11. from net_engine.plist_dock import PListDock
  12. from net_engine.client_gear import ClientGear
  13. from tree_engine.tree_dock import TreeDock
  14. from tool_gears.path_gear import PathTool, path
  15.  
  16. PathTool().load_paths(path)
  17.  
  18. class MainWindow(QtGui.QMainWindow):
  19.  
  20.     def __init__(self):
  21.         super(MainWindow, self).__init__()
  22.         self.setWindowIcon(QtGui.QIcon(path['core_images'] + 'traipse-logo-2.png'))
  23.         self.client = ClientGear(self)
  24.         self.createActions()
  25.         self.createDocks()
  26.         self.StatusBar('Ready')
  27.         self.createToolBar()
  28.         self.createStyle()
  29.         self.setCentralWidget(self.center1)
  30.  
  31.     def createDocks(self):
  32.         #Game Tree Docking Bay
  33.         self.treeDock = QtGui.QDockWidget("Dock-Game Tree", self)
  34.         self.center4 = TreeDock(self, self.client)
  35.         self.treeDock.setWidget(self.center4)
  36.         self.treeDock.setFeatures(QtGui.QDockWidget.DockWidgetMovable | 
  37.                 QtGui.QDockWidget.DockWidgetFloatable)
  38.         self.center4.add('Child-2')
  39.         self.addDockWidget(QtCore.Qt.LeftDockWidgetArea, self.treeDock)
  40.  
  41.         #Player List Docking Bay
  42.         self.PlayerList = QtGui.QDockWidget("Dock-Player List", self)
  43.         self.center3 = PListDock(self, self.client)
  44.         self.PlayerList.setWidget(self.center3)
  45.         self.PlayerList.setFeatures(QtGui.QDockWidget.DockWidgetMovable | 
  46.                 QtGui.QDockWidget.DockWidgetFloatable)
  47.         self.center3.add(2, 'Player-2', 'Idle')
  48.         self.center3.add(3, 'Player-3', 'Typing')
  49.         self.addDockWidget(QtCore.Qt.LeftDockWidgetArea, self.PlayerList)
  50.  
  51.         #Map Docking Bay
  52.         self.mapDock = QtGui.QDockWidget("Dock-Map", self)
  53.         self.center1 = MapDock(self, self.client)
  54.         self.mapDock.setWidget(self.center1)
  55.         self.mapDock.setFeatures(QtGui.QDockWidget.DockWidgetMovable | 
  56.                 QtGui.QDockWidget.DockWidgetFloatable)
  57.         self.addDockWidget(QtCore.Qt.RightDockWidgetArea, self.mapDock)
  58.         self.mapDock.hide()
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This is the Main file. This is my anchor to all my other UI scripts. This is not a complete version, but here you can see I am creating a proxy Player List and proxy Game Tree. I want you to look at the Map Docking Bay. It inserts the MapDock class, passing the parent and the future network client.

map_dock.py
Qt Code: 
  1. from PyQt4 import QtCore, QtGui
  2. from tool_gears.path_gear import path
  3. from map_engine.tool_gear import mapToolGear
  4. from map_engine.map_gear import MapDocket
  5.  
  6. class MapDock(QtGui.QMainWindow):
  7.  
  8.     def __init__(self, parent, client):
  9.         super(MapDock, self).__init__()
  10.         self.parent = parent; self.client = client
  11.         self.createMap()
  12.         self.createToolBar()
  13.         self.setCentralWidget(self.mapDocket)
  14.  
  15.     def createToolBar(self):
  16.         self.ToolBay = mapToolGear(self.parent)
  17.         self.addToolBar(QtCore.Qt.BottomToolBarArea, self.ToolBay)
  18.  
  19.     ## Map Docket
  20.     def createMap(self):
  21.         self.mapDocket = QtGui.QWidget()
  22.         layout = QtGui.QGridLayout()
  23.         self.mapView = MapDocket()
  24.         layout.addWidget(self.mapView)
  25.         self.mapDocket.setLayout(layout)
  26.  
  27.     def createMapEditor(self):
  28.         self.parent.mapEditor = QtGui.QDialog()
  29.         layout = QtGui.QGridLayout()
  30.         self.parent.mapEditView = MapDocket()
  31.         layout.addWidget(self.parent.mapEditView)
  32.         self.parent.mapEditor.setLayout(layout)
  33.         self.parent.mapEditor.show()
  34.  
  35.     def empty(self):
  36.         pass
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Here is the entirety of my map_dock file, which contains the MapDock class. Can you see how I am re using the MapDocket() class to create a map for the core software and a map for the map editor? Maybe I am wrong, but I think that is what you are trying to do. Notice how the second one is rooted in the parent?

I would suggest you look at your Ui_Dialog Classes. They don't need to declared (object), the should be declared (QtGui.QDialog). I am also not sure why you would create a setupUI function and not use the pre-built __init__ function. I would suggest you use __init__ and then you can create room for you parent object, plus you can build the UI just by calling the class each time.