With the "flash" USE flag, PHP gets compiled with ming. Version 4.2.0 of PHP needs 0.2a of ming, but there's only an ebuild for 0.1.1 (and the ming version requirement isn't recorded in the ebuild).
In bug #2710 is an updated package for ming that should work.
Ming 0.2a is now in the archive, and this should work. As an updated php ebuild is in the works, I'll hold off on specifically requiring a ming >= 0.2a until the build is finished.
I've merged mod_php 4.3.2-r3 and apache 1.3.27-r4 and configured both. the presence of mod_php is preventing apache from binding to :80 and from responding to requests. (see forum topic http://forums.gentoo.org/viewtopic.php?t=68136 for configuration details) /var/log/apache/error_log: Syntax error on line 57 of /etc/apache/conf/apache.conf: Cannot load /etc/apache/extramodules/libphp4.so into server: /usr/lib/libming.so: R_PPC_REL24 relocation at 0x0d1a3a38 for symbol `' out of range