Restart is not required to create a zombie. Just start IDLE and quit, and the second, user process does not disappear.

Reverting completely does not seem possible. I first just ran the 3.2 installer and it did not complain, that I noticed, about replacing a newer version, but apparently only replaced .exe and .dll and a few other files but not Lib/*.py. Idle or command prompt window said it was still 3.2.1 and the bug remained.

So I uninstalled, deleted everything left except my .py files in site-packages and another subdirectory, and reinstalled 3.2. Now everything seems to predate 2/22/2011. BUT IDLE and command prompt window *still* report "Python 3.2.1 (default, Jul 10 2011, 21:51:15) [MSC v.1500 32 bit (Intel)] on win32". This is sys.version. Something somewhere (registry?) seems to not be deleted by uninstall.  And the bug remains. Could a registry entry possibly affect this?

My system is 7 years old with updated win xp 32 bit.

I then checked the never updated 64 bit Py 3.2 on an 18 month old 64 bit Win 7 laptop and detached user processes *do* disappear as I remember on this machine. It did, however, take 8 sec over restart and 12 after closing, which is longer than I remember for my older and definitely slower machine.