[Zope] External method: import error

Hi Zopiens! I'll start with one question... is Zope stable to use thus far? Anyway, back to my problem. I have Zap (pre-built Zope with Apache) running on Red Hat 5.2 machine. I also put all my customize Python scripts in the Extensions directory of Zope. Recently I wrote a script file to access a Postgres database and this file is called by other scripts whenever database access is needed. Now I got a problem of "importing" the database script from other scripts. Why so? I have tried to include the Extensions directory in the PYTHONPATH, but it doesn't work. Thanks for any suggestion or solution given. PauL ChunG