Hi!
There is a missing entry point for the mkzeoinst.py script in ZODB3-3.5.1:
if __name__=="__main__":
     main()
Regards,
Tamas
-- 
Tamas Hegedus, PhD          | phone: (1) 919-966 0329
UNC - Biochem & Biophys     | fax:   (1) 919-966 5178
5007A Thurston-Bowles Bldg  | mailto:hegedus at med.unc.edu
Chapel Hill, NC, 27599-7248 | http://biohegedus.org