TkAgg backend error message running within IPython

I'm getting the error:

can't invoke "event" command: application has been destroyed
    while executing
"event generate $w <<ThemeChanged>>"
    (procedure "ttk::ThemeChanged" line 6)
    invoked from within
"ttk::ThemeChanged"

With the latest matplotlib 1.0.0 on 64-bit Ubuntu 10.04 running the
following script within IPython 0.10 in pylab mode:

import matplotlib.pyplot as plt
import numpy as np

def test():
    plt.figure(figsize=(10,5))
    plt.plot(np.arange(1, 51), np.arange(1, 51), color='k')

def make_figs():
    test()
    plt.savefig('foo.pdf')
    plt.close('all')

if __name__ == '__main__':
    make_figs()

Here's the build information:

wesm@...3303...:~/code/repos/matplotlib$ sudo python setupegg.py develop
basedirlist is: ['/usr/local', '/usr']

···

============================================================================
BUILDING MATPLOTLIB
            matplotlib: 1.0.0
                python: 2.6.5 |EPD 6.2-2 (64-bit)| (r265:79063, Mar 22 2010,
                        17:32:05) [GCC 4.1.2 20080704 (Red Hat 4.1.2-44)]
              platform: linux2

REQUIRED DEPENDENCIES
                 numpy: 1.4.0
             freetype2: 9.22.3

OPTIONAL BACKEND DEPENDENCIES
                libpng: 1.2.42
               Tkinter: Tkinter: 73770, Tk: 8.5, Tcl: 8.5
                        * Guessing the library and include directories for
                        * Tcl and Tk because the tclConfig.sh and
                        * tkConfig.sh could not be found and/or parsed.
                  Gtk+: no
                        * Building for Gtk+ requires pygtk; you must be able
                        * to "import gtk" in your build/install environment
       Mac OS X native: no
                    Qt: no
                   Qt4: no
                 Cairo: no

OPTIONAL DATE/TIMEZONE DEPENDENCIES
              datetime: present, version unknown
              dateutil: 1.5
                  pytz: 2010h

OPTIONAL USETEX DEPENDENCIES
                dvipng: 1.12
           ghostscript: 8.71
                 latex: 3.1415926
               pdftops: 0.12.4

[Edit setup.cfg to suppress the above messages]

I checked that EPD 6.2.2 was built with tk8.5/tcl8.5 in case that was
causing a problem, does not seem to be.

I can switch to the WXAgg backend for now, but would help to know if
I'm doing something wrong by chance.

Note: I do not get this message running the script standalone outside
of IPython!

Thanks,
Wes