wx.BoxSizer problem

[Laszlo Zsolt Nagy]

 Hi All,

Here is the code of a frame:

import wx
class PanelDatabaseDefinition(wx.Panel):
   def __init__(self,parent):
       wx.Panel.__init__(self,parent)
       self.sizer = wx.BoxSizer(wx.VERTICAL)
       self.SetSizer(self.sizer)
       
self.sizer.Add(wx.Button(self,label="test1"),flag=wx.EXPAND,proportion=1)
       
self.sizer.Add(wx.Button(self,label="test2"),flag=wx.EXPAND,proportion=1)

class FrameDatabaseDefinition(wx.Frame):
   def __init__(self,parent,title):
       wx.Frame.__init__(self,parent,title=title)
       self.panel = PanelDatabaseDefinition(self)
       self.sizer = wx.BoxSizer(wx.VERTICAL)
       self.SetSizer(self.sizer)
       self.sizer.Add(self.panel,flag=wx.EXPAND,proportion=1)
       self.Layout()

I would like to use the panel PanelDatabaseDefinition on the frame 
FrameDatabaseDefinition, but I should also be able to use the panel on 
other frames. (A la "Delphi frames".) My problem is that only one of the 
buttons is visible and that one is not expanded. (System: Windows, 
Python 2.3.4, wxPython 2.5.3)
Best,

  Laci