Cannot understand the difference between an Apache with EA..

I have downloaded mod_jk.so from the Tomcat site and when I attempt to use it via the LoadModule directive I get an error that is explained as follows:

Q. What's that message about 'garbled DSO ?'
A. It's related to Apache EAPI, the message 'mod_jk.so is garbled - perhaps this is not an Apache module DSO ?' just told you are trying to install a mod_jk.so DSO module that was compiled on an Apache using EAPI, like apache-mod_ssl or apache from Redhat distro 6.2/7.0 but your system use the standard apache with normal API.

What does it mean to have an Apache system using the normal API versus the EAPI. Is there a setting in Apache 2.2 to force the use of EAPI so that I can use the precompiled mod_jk.so?

Environment: Tomcat 5.5, Apache 2.2 and Fedora Core 5.