Hi all the php developers, I'm testing php-4.3.0 in RedHat 8.0,httpd-2.0.40 from redhat packages, I built rpms for this plataform with pdf support with pdflib-4.0.3, here my configure...
%configure \
	--prefix=%{_prefix} \
	--with-config-file-path=%{_sysconfdir} \
	--enable-force-cgi-redirect \
	--disable-debug \
	--enable-pic \
	--disable-rpath \
	--enable-inline-optimization \
	--with-bz2 \
	--with-db3 \
	--with-curl \
	--with-dom=%{_prefix} \
	--with-exec-dir=%{_bindir} \
	--with-freetype-dir=%{_prefix} \
	--with-png-dir=%{_prefix} \
	--with-gd \
	--enable-gd-native-ttf \
	--with-ttf \
	--with-gdbm \
	--with-gettext \
	--with-pdflib=shared \
	--with-tiff-dir=%{_prefix} \
	--with-ncurses \
	--with-gmp \
	--with-iconv \
	--enable-xslt=shared \
	--with-jpeg-dir=%{_prefix} \
	--with-openssl \
	--with-png \
	--with-pspell \
	--with-regex=system \
	--with-xml \
	--with-expat-dir=%{_prefix} \
	--with-zlib \
	--with-layout=GNU \
	--enable-bcmath \
	--enable-exif \
	--enable-ftp \
	--enable-magic-quotes \
	--enable-safe-mode \
	--enable-sockets \
	--enable-sysvsem \
	--enable-sysvshm \
	--enable-discard-path \
	--enable-track-vars \
	--enable-trans-sid \
	--enable-yp \
	--enable-wddx \
	--without-oci8 \
	--with-pear=/usr/share/pear \
	--with-imap=shared \
	--with-imap-ssl \
	--with-kerberos=/usr/kerberos \
	--with-ldap=shared \
	--with-mcal=shared,%{_prefix} \
	--with-mcrypt=shared,%{_prefix} \
	--with-mhash=shared,%{_prefix} \
	--with-mysql=shared,%{_prefix} \
%if %{oracle}
	--with-oci8=shared \
%endif
	--with-pgsql=shared \
	--with-snmp=shared,%{_prefix} \
	--with-snmp=shared \
	--with-sybase-ct=shared,%{_prefix} \
	--with-xslt-sablot=shared,%{_prefix} \
	--with-sablot-js=shared,%{_prefix} \
	--enable-ucd-snmp-hack \
	--with-unixODBC=shared \
	--enable-memory-limit \
	--enable-bcmath \
	--enable-shmop \
	--enable-versioning \
	--enable-calendar \
	--enable-dbx \
	--enable-dio \
	--enable-mcal \

and when I include in my php.ini the pdflib extensions the httpd server crash and fail to start,in the past php-4.2.4-dev was ok, this is the apache log error,  
[Wed Nov 13 00:41:57 2002] [notice] caught SIGTERM, shutting down
/usr/sbin/httpd: relocation error: /usr/lib/php4/pdf.so: undefined symbol: PDF_get_majorversion
/usr/sbin/httpd: relocation error: /usr/lib/php4/pdf.so: undefined symbol: PDF_get_majorversion
/usr/sbin/httpd: relocation error: /usr/lib/php4/pdf.so: undefined symbol: PDF_get_majorversion

                                   I hope helps, bye aliet