TkAgg init problem in matplotlib-0.53

I'm trying to run the first tutorial example in matplotlib-0.53 and am running into an ImportError. Here's the python script I'm trying to run:

import matplotlib
matplotlib.use('TkAgg')
from matplotlib.matlab import *
plot([1,2,3,4])
show()

Here's the output I'm getting:

light:gerry> python matplotlibtest.py
Traceback (most recent call last):
  File "matplotlibtest.py", line 15, in ?
    from matplotlib.matlab import *
  File "/d2/gerry/local/ActivePython-2.3/lib/python2.3/site-packages/matplotlib/matlab.py", line 129, in ?
    from backends import new_figure_manager, error_msg, \
  File "/d2/gerry/local/ActivePython-2.3/lib/python2.3/site-packages/matplotlib/backends/__init__.py", line 29, in ?
    from backend_tkagg import error_msg, draw_if_interactive, show, new_figure_manager
  File "/d2/gerry/local/ActivePython-2.3/lib/python2.3/site-packages/matplotlib/backends/backend_tkagg.py", line 8, in ?
    import tkagg # Paint image to Tk photo blitter extension
  File "/d2/gerry/local/ActivePython-2.3/lib/python2.3/site-packages/matplotlib/backends/tkagg.py", line 1, in ?
    import _tkagg
ImportError: /d2/gerry/local/ActivePython-2.3/lib/python2.3/site-packages/matplotlib/backends/_tkagg.so: undefined symbol: XFreePixmap

Thanks for any help.

--Gerry Wiener