Wxpython GUI is not same on python2

Question

I'm trying to change the code written in python3 to python2.4. Python3 version code run on window well but in python2.4 and Centos5.11, GUI is not same even it run same code.

in window, python3

in centos, python2.4

The gui code is below:

class Panel(wx.Panel):
global WTIME
def __init__(self, parent, site):
    wx.Panel.__init__(self, parent,wx.ID_ANY, pos=wx.DefaultPosition, size=wx.Size(600,100), style=wx.TAB_TRAVERSAL)
    self.site = site
    bSizer = wx.BoxSizer(wx.VERTICAL)
    self.canvas = PlotCanvas(self, 0)
    self.canvas.SetYSpec("none")
    self.canvas.Draw(drawBarGraph(self.site), xAxis=(0,12), yAxis=(0,1))
    bSizer.Add(self.canvas, 1, wx.EXPAND)
    self.SetSizer(bSizer)
    self.canvas.SetEnableGrid(False)
    self.Layout()

def updateGraph(self, site_log):
    self.canvas.Draw(drawBarGraph(self.site, site_log), xAxis=(0,WTIME), yAxis=(0,1))

class MainFrame(wx.Frame):
def __init__(self):
    """Constructor"""
    wx.Frame.__init__(self, None, title="NoName", size=(1250,500))
    self.scroll = wx.ScrolledWindow(self, -1, size=(1250,500))
    self.scroll.SetScrollbars(1,1,1400,1600)

    topSizer = wx.BoxSizer(wx.VERTICAL)

    panelSizer1 = wx.BoxSizer(wx.HORIZONTAL)
    panelSizer2 = wx.BoxSizer(wx.HORIZONTAL)
    panelSizer3 = wx.BoxSizer(wx.HORIZONTAL)
    panelSizer4 = wx.BoxSizer(wx.HORIZONTAL)
    self.p1 = Panel(self.scroll, "SITE1")
    self.p2 = Panel(self.scroll, "SITE2")
    self.p3 = Panel(self.scroll, "SITE3")
    self.p4 = Panel(self.scroll, "SITE4")
    self.p5 = Panel(self.scroll, "SITE5")
    self.p6 = Panel(self.scroll, "SITE6")
    self.p7 = Panel(self.scroll, "SITE7")
    self.p8 = Panel(self.scroll, "SITE8")
    self.panels = [self.p1, self.p2, self.p3, self.p4, self.p5, self.p6, self.p7, self.p8]

    panelSizer1.Add(self.p1, 0, wx.ALL|wx.EXPAND,5)
    panelSizer1.Add(self.p2, 0, wx.ALL|wx.EXPAND,5)
    panelSizer2.Add(self.p3, 0, wx.ALL|wx.EXPAND,5)
    panelSizer2.Add(self.p4, 0, wx.ALL|wx.EXPAND,5)
    panelSizer3.Add(self.p5, 0, wx.ALL|wx.EXPAND,5)
    panelSizer3.Add(self.p6, 0, wx.ALL|wx.EXPAND,5)
    panelSizer4.Add(self.p7, 0, wx.ALL|wx.EXPAND,5)
    panelSizer4.Add(self.p8, 0, wx.ALL|wx.EXPAND,5)

    topSizer.Add(panelSizer1, 0, wx.ALL|wx.EXPAND, 5)
    topSizer.Add(panelSizer2, 0, wx.ALL|wx.EXPAND, 5)
    topSizer.Add(panelSizer3, 0, wx.ALL|wx.EXPAND, 5)
    topSizer.Add(panelSizer4, 0, wx.ALL|wx.EXPAND, 5)
    self.scroll.SetSizer(topSizer)
    topSizer.Fit(self.scroll)



    menu = wx.Menu()
    windowtimemenu = menu.Append(101, "Set Window Time", "Minute")
    self.Bind(wx.EVT_MENU, self.OnSetWtime, windowtimemenu)
    menu.Append(wx.ID_ABOUT, "About", "About")
    exitmenu = menu.Append(wx.ID_EXIT, "EXIT", "Close")
    self.Bind(wx.EVT_MENU, self.OnExit, exitmenu)
    menubar = wx.MenuBar()
    menubar.Append(menu, "Menu")
    self.Bind(wx.EVT_CLOSE, self.OnCloseWindow)
    self.e = threading.Event()
    self.SetMenuBar(menubar)

    self.Show()

My questions...

1. Does wxpython run differently on py2, py3?
2. How can I show the same GUI on centos like windows.