make install:
(....)
Making install in .
/usr/local/archive/php/php-4.0.6/build/shtool mkdir -p "/usr/local/apache/libexec" && /usr/local/apache/bin/apxs -S LIBEXECDIR="/usr/local/apache/libexec" -i -a -n php4 libs/libphp4.so
[activating module `php4' in /usr/local/apache/conf/httpd.conf]
cp libs/libphp4.so /usr/local/apache/libexec/libphp4.so
apxs:Break: Command failed with rc=16777215
*** Error code 1

Stop in /usr/local/archive/php/php-4.0.6 (line 39 of Makefile).
*** Error code 1

Stop in /usr/local/archive/php/php-4.0.6 (line 37 of /usr/local/archive/php/php-4.0.6/build/rules.mk).
---
./configure \
--with-mysql=/usr/local/mysql \
--with-apxs=/usr/local/apache/bin/apxs \
--with-mm=/usr/local
---
# verified httpd is capable of php as dso:
/opt/apache/bin/httpd -l
# saw http_core.c & mod_so.c compiled in
---
/usr/local/apache/bin/apxs -q:
CC             = gcc
CFLAGS         = -DMOD_SSL=208104
CFLAGS_SHLIB   = -DMOD_SSL=208104 -DEAPI -DUSE_EXPAT -I../lib/expat-lite
LD_SHLIB       = gcc
LDFLAGS_SHLIB  = -shared -fPIC -DSHARED_MODULE
LIBS_SHLIB     = 
TARGET         = httpd
SBINDIR        = /usr/local/apache/bin
INCLUDEDIR     = /usr/local/apache/include
LIBEXECDIR     = /usr/local/apache/libexec
SYSCONFDIR     = /usr/local/apache/conf
PREFIX         = /usr/local/apache
---
thank you for your thoughts! i appreciate it...