Memory leak & Tkinter?

First, I'm new to Matplotlib (and Python!), so apologies in
advance if I'm missing something obvious.

I'm running on XP, Numpy ver. 1.0.1, Matplotlib ver.
0.87.7, Python ver. 2.4.3

I'm trying to create several plots. I noticed that after
saving each plot my script's memory footprint increases by
about 5MB. So I quickly run out of system memory. I
thought maybe I wasn't closing the figure properly. I
tried the code given in the FAQ and I get the same results.
I tried calling gc.collect() but it didn't help. I
noticed that after calling gc.collect(), gc.garbage returns
359 <Tkinter.PhotoImage> objects. I'm guessing these are
the bad boys who won't go away. Why are they still there
and why aren't they being "collected"?

Any ideas?

Thanks in advance!

ps. For what it's worth, here's the code (simplified)
looks like... nothing fancy:

                (a,b,c) = hist(data, 10)
                savefig(os.path.join("Plots", paramName))
                close() I said, the code from the "memory leak" FAQ also
seems to give me the same problem.