Description of problem: If you write a program that uses /usr/include/Poco/XML/ParserEngine.h then it will not compile if you haven't already installed expat-devel. This is because expat.h is included in ParserEngine.h. I suspect that it just needs a dependency on the RPM so it pulls in expat-devel when you install Poco-devel.
Wasn
poco-1.3.5-9.el5 has been submitted as an update for Fedora EPEL 5. https://admin.fedoraproject.org/updates/poco-1.3.5-9.el5
poco-1.3.5-9.el6 has been submitted as an update for Fedora EPEL 6. https://admin.fedoraproject.org/updates/poco-1.3.5-9.el6
poco-1.3.5-9.el6 has been pushed to the Fedora EPEL 6 testing repository. If problems still persist, please make note of it in this bug report. If you want to test the update, you can install it with su -c 'yum --enablerepo=updates-testing update poco'. You can provide feedback for this update here: https://admin.fedoraproject.org/updates/poco-1.3.5-9.el6
poco-1.3.5-9.el6 has been pushed to the Fedora EPEL 6 stable repository. If problems still persist, please make note of it in this bug report.
poco-1.3.5-9.el5 has been pushed to the Fedora EPEL 5 stable repository. If problems still persist, please make note of it in this bug report.