[Zope] Pyexpat and Zope 2.9.5

Dear list, I am trying to get Zope 2.9.5 compiled with Python 2.4.3 using the python-ldap module. I compiled my own Python and copied the site-packages, so the ldap module is available. When I run "import ldap", the module is imported correctly. Then I run "configure" in my Zope folder, which gives me the notification that I need pyexpat installed. However, I do have the pyexpat.so exactly in the run path that it should be (the path is also printed in the error message). Is this a known problem or could you give me advice what I am doing wrong? If I compile Zope with the --ignore-expat option, then I get the following error message ('xml.sax.drivers2.drv_pyexpat'), so this is not an option for me. Thanks, Fabian