Log below.

It appears PHP 4.1.2 doesn't like apache 1.3.23...?

Configure command (dir variables are defined in a shell 
include I use for convenience):

./configure \
        --prefix=${PHP_MOD_PREFIX_DIR} \
        --with-config-file-path=${APACHE_PREFIX_DIR}/conf \
        --with-apache=../${APACHE_DIR} \
        --enable-ftp \
        --with-zlib \
        --enable-bcmath \
        --enable-calendar \
        --with-jpeg-dir=/usr/lib \
        --with-imlib=/usr/local/lib/ \
        --with-iconv=/usr/local/lib \
        --with-tiff-dir=/usr/lib \
        --with-oci8=${ORACLE_DIR} \
        --with-sapdb=/opt/sapdb/interfaces/odbc \
        --with-mhash=${MHASH_PREFIX_DIR} \
        --with-mcrypt=${MCRYPT_PREFIX_DIR} \
        --with-dom=${LIBXML2_PREFIX_DIR} \
        --enable-xslt --with-xslt-sablot=${SAB_PREFIX_DIR} 
\
        --with-curl=${CURL_PREFIX_DIR} \
        --with-expat-dir=${EXPAT_PREFIX_DIR} \
        --enable-wddx \
        --enable-memory-limit \
        --with-mm=${MM_PREFIX_DIR} \
        --enable-debug=no


---------------

Log:

make[2]: Entering directory 
`/root/bc_install/packages/php-4.1.2.mod/sapi/apache'
make[3]: Entering directory 
`/root/bc_install/packages/php-4.1.2.mod/sapi/apache'
gcc -I. 
-I/root/bc_install/packages/php-4.1.2.mod/sapi/apache 
-I/root/bc_install/packages/php-4.1.2.mod/main 
-I/root/bc_install/packages/php-4.1.2.mod 
-I/root/bc_install/packages/apache_1.3.23/src/include 
-I/root/bc_install/packages/apache_1.3.23/src/os/unix 
-I/root/bc_install/packages/php-4.1.2.mod/Zend 
-I/usr/local/curl/include 
-I/usr/local/libxml2/include/libxml2 -I/usr/local/include 
-I/usr/local/mcrypt/include -I/usr/local/mhash/include 
-I/root/bc_install/packages/php-4.1.2.mod/ext/mysql/libmysq
l -I/u01/oracle/product/8.1.6/rdbms/public 
-I/u01/oracle/product/8.1.6/rdbms/demo 
-I/u01/oracle/product/8.1.6/network/public 
-I/opt/sapdb/interfaces/odbc/incl -I/usr/local/mm/include 
-I/usr/local/expat/include -I/usr/local/Sablot/include 
-I/root/bc_install/packages/apache_1.3.23/src/include 
-I/root/bc_install/packages/apache_1.3.23/src/os/unix 
-I/root/bc_install/packages/php-4.1.2.mod/TSRM -g -O2  -c 
sapi_apache.c && touch sapi_apache.lo
In file included from 
/root/bc_install/packages/apache_1.3.23/src/include/ap_conf
ig.h:77,
                 from 
/root/bc_install/packages/apache_1.3.23/src/include/httpd.h
:72,
                 from sapi_apache.c:32:
/root/bc_install/packages/apache_1.3.23/src/include/ap_conf
ig_auto.h:6: unterminated `#if' conditional
In file included from 
/root/bc_install/packages/apache_1.3.23/src/include/httpd.h
:72,
                 from sapi_apache.c:32:
/root/bc_install/packages/apache_1.3.23/src/include/ap_conf
ig.h:1386: warning: `XtOffsetOf' redefined
/root/bc_install/packages/php-4.1.2.mod/main/php.h:342: 
warning: this is the location of the previous definition
make[3]: *** [sapi_apache.lo] Error 1
make[3]: Leaving directory 
`/root/bc_install/packages/php-4.1.2.mod/sapi/apache'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory 
`/root/bc_install/packages/php-4.1.2.mod/sapi/apache'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory 
`/root/bc_install/packages/php-4.1.2.mod/sapi'
make: *** [all-recursive] Error 1