How to make Panel Size >= MinSize?

In the following code, the Frame ends up being too small, one of the panels
inside it is shorter than its MinSize. How do I go about correcting this?

The panel's MinSize is (203, 121) but its size is (361, 110)

Thanks.

import wx

class MainFrame(wx.Frame):
    
    def __init__(self, *args, **kwds):
        kwds["style"] = wx.MINIMIZE_BOX | wx.RESIZE_BORDER | wx.SYSTEM_MENU

wx.CAPTION | wx.CLOSE_BOX | wx.CLIP_CHILDREN

        wx.Frame.__init__(self, *args, **kwds)
        
        self.SetTitle("The Title")
                
        self.mainStatusBar = self.CreateStatusBar(number=1)
        
        #Main background area
        self.panelMain = wx.Panel(self, wx.ID_ANY)
        self.sizerMain = wx.BoxSizer(wx.VERTICAL)
        self.panelMain.SetSizer(self.sizerMain)
                 
        self.__SetUpToolbar()
                
        #Tabs
        self.tabs = wx.Notebook(parent=self.panelMain, id=wx.ID_ANY,
                                style=wx.NB_TOP)
        self.sizerMain.Add(item=self.tabs, proportion=1,
                          flag=wx.EXPAND | wx.ALL, border=5)
        
        #Tab1
        self.tabMain = wx.Panel(parent=self.tabs, id=wx.ID_ANY)
        self.sizerTabMain = wx.BoxSizer(wx.VERTICAL)
        self.tabMain.SetSizer(self.sizerTabMain)
        
        self.tabMainInner = wx.Panel(parent=self.tabMain, id=wx.ID_ANY)
        self.sizerTabMain.Add(item=self.tabMainInner, proportion=1,
                              flag=wx.EXPAND | wx.ALL, border=10)
        self.tabMainBox = wx.StaticBox(parent=self.tabMainInner,
                                       id=wx.ID_ANY, label="Database")
        
        self.sizerTabMainInner = wx.StaticBoxSizer(box=self.tabMainBox,
                                                   orient=wx.VERTICAL)
        self.tabMainInner.SetSizer(self.sizerTabMainInner)
        
        self.tabs.AddPage(page=self.tabMain, text="General", select=True)
        
        #Tab1 - Line 1
        self.staticTextLine1 = \
            wx.StaticText(parent=self.tabMainInner, id=wx.ID_ANY,
                          label="This is a long string with lots of words.")
        self.sizerTabMainInner.Add(item=self.staticTextLine1,
                                   proportion=0,
                                   flag=wx.TOP | wx.BOTTOM | wx.LEFT,
                                   border=10)
        
        #Tab1 - Line 2
        self.staticTextLine2 = \
            wx.StaticText(parent = self.tabMainInner, id = wx.ID_ANY,
                          label = "Line 2")
        self.sizerTabMainInner.Add(item=self.staticTextLine2,
                                   proportion=0,
                                   flag=wx.TOP | wx.BOTTOM | wx.LEFT,
                                   border=10)
        
        #Tab1 - The Button
        self.theButton = wx.Button(parent=self.tabMainInner, id=wx.ID_ANY,
                                   label="The Button")
        self.sizerTabMainInner.Add(item=self.theButton, proportion=0,
                                   flag=wx.ALIGN_RIGHT | wx.LEFT |
                                   wx.RIGHT | wx.BOTTOM,
                                   border=10)
        
        #Sizing
        tabMainInnerSize = self.tabMainInner.GetBestSize()
        self.tabMainInner.SetMinSize(tabMainInnerSize)
        
        print "tabMainInner MinSize set to:", tabMainInnerSize
        
        self.Layout()
        self.Fit()
        self.Refresh()
        
        print "tabMainInner Size at end:", self.tabMainInner.GetSize()
        print "tabMainInner MinSize at end:", self.tabMainInner.GetMinSize()

    def __OnStatus(self, evt):
        pass

    def __SetUpToolbar(self):
        self.__TB_ID_STATUS = 10
                
        self.__tb = self.CreateToolBar(style=wx.TB_HORIZONTAL | wx.NO_BORDER

wx.TB_FLAT)

        wx.ART_FILE_SAVE

        tsize = (32, 32)
        self.__tb.SetToolBitmapSize(tsize)
        
        statusBmp = wx.ArtProvider_GetBitmap(wx.ART_HELP, wx.ART_OTHER,
tsize)
        
        self.__tb.AddSimpleTool(id=self.__TB_ID_STATUS, bitmap=statusBmp,
shortHelpString="Status", longHelpString="Get the status of the radio
network.")
        self.Bind(wx.EVT_TOOL, self.__OnStatus, id=self.__TB_ID_STATUS)
        
        self.__tb.Realize()
        
class MyApp(wx.App):
    def OnInit(self):
        frame = MainFrame(None, wx.ID_ANY)
        frame.Show(True)
        self.SetTopWindow(frame)
        return True

app = MyApp(False) #False prevents wxWidgets from using own console
app.MainLoop()