The test program depends on an external third-party module graphics.  
From the problem description and a web search, I assume the file is:

   http://mcsp.wartburg.edu/zelle/python/graphics.py

Can you confirm that?

Using that module, target.py runs on 10.5 invoking python2.6 directly 
with Apple-supplied Tk 8.4.7 or under idle2.6.  However, with a 
python2.6 using ActiveState Tk 8.4.19 installed on 10.5 or 10.6, 
target.py fails with:
Tk_MacOSXSetupTkNotifier: first [load] of TkAqua has to occur in the 
main thread!

As of 10.6(.2), attempts to run with a Tkinter linked to the Apple-
suppled Tk 8.5.7 hang (similar problems noted with other apps).

I was not able to reproduce the error message your report but there are 
certainly known and/or suspected issues with Tkinter and Apple's Tk 
8.4.7, even more likely running under IDLE which uses Tkinter itself.  

I'm not sure what action to recommend with this issue.  Perhaps it makes 
the most sense to leave it open until Tkinter with Apple Tk 8.5 is 
working reliably and then retest.

BTW, the message "IDLE can't bind TCP/IP port 8833" most likely 
indicates one of the IDLE processes has aborted leaving another waiting 
for the socket to close.  Ideally, that shouldn't happen.

Thanks for the problem report.