Error in dock.py?

[Charles R. McCreary]

Line 378 in dock.py:
headerBox.Add(1, 5, 1, wxGROW)
I get the following exception:
TypeError: wx.Window, wx.Sizer, wx.Size, or (w,h) expected for item
What is being added to the static box sizer?
This the released version
ubuntu edgy
wx 2.6.3
python 2.4