no plot figures on Solaris with TkAgg

Hi,
I am new to matplotlib and just installed it in my home directory as
an egg along with numpy and pytz on Solaris 10. Building matplotlib
using setupegg.py bdist_egg worked out just fine. But when I am
trying to run the simple_plot.py example or do an interactive plot([1,
2, 3]); show(), all I get is the Tk window frame and an empty plotting
area.
Below is the output I got from --verbose-helpful:

python simple_plot.py --verbose-helpful

$HOME=/home/shauer
CONFIGDIR=/home/shauer/.matplotlib
matplotlib data path
/home/shauer/sys/py/lib/matplotlib-0.98.1-py2.5-solaris-2.10-sun4u.egg/matplotlib/mpl-data
loaded rc file /home/shauer/sys/py/lib/matplotlib-0.98.1-py2.5-solaris-2.10-sun4u.egg/matplotlib/mpl-data/matplotlibrc
matplotlib version 0.98.1
verbose.level helpful
interactive is False
units is False
platform is sunos5
Using fontManager instance from /home/shauer/.matplotlib/fontManager.cache
numerix numpy 1.1.0
backend TkAgg version 8.5

Any help is appreciated,
Sebastian