Report http://bugs.php.net/?id=8410
fixes some issues with compiling php for apache2,
these fixes are in the latest cvs (10/01/2001).

Compiled Apache with 

./configure --with-mpm=prefork --enable-cache --enable-disk-cache --enable-vhost-alias --enable-status --enable-speling --enable-suexec --enable-so --enable-shared=max --prefix=/web/server/apache2

Runs fine, compiled php with

./configure --with-mysql=/web/server/mysql --enable-inline-optimization --enable-memory-limit --enable-sysvsem --enable-sysvshm --with-zlib --with-apxs2=/web/server/apache2/bin/apxs --disable-pear --with-mm=/usr/local

restart apache results in core dump and sig11:

There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-unknown-freebsd"...
Core was generated by `httpd'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /web/kit/2/apache_2.0a9/srclib/apr-util/.libs/libaprutil.so.0...done.
Reading symbols from /usr/lib/libcrypt.so.2...done.
Reading symbols from /usr/lib/libc_r.so.4...done.
Reading symbols from /web/server/apache2/libexec/libphp4.so...done.
Reading symbols from /usr/lib/libpam.so.1...done.
Reading symbols from /usr/lib/libstdc++.so.3...done.
Reading symbols from /usr/lib/libz.so.2...done.
Reading symbols from /usr/local/lib/libmm.so.11...done.
Reading symbols from /web/server/mysql/lib/mysql/libmysqlclient.so.10...done.
Reading symbols from /usr/lib/libm.so.2...done.
Reading symbols from /usr/lib/libc.so.4...done.
Reading symbols from /usr/libexec/ld-elf.so.1...done.
#0  0x28149b9e in strchr () from /usr/lib/libc_r.so.4
(gdb) bt
#0  0x28149b9e in strchr () from /usr/lib/libc_r.so.4
#1  0x281dffdc in php_register_hook () at sapi_apache2.c:436
#2  0x8076356 in ap_post_config_hook (pconf=0x80ec00c, plog=0x813100c, ptemp=0x813400c, s=0x80ecf64) at config.c:1712
#3  0x8077867 in main (argc=1, argv=0xbfbffc08) at main.c:396
#4  0x80551a5 in _start ()

Please let me know how I can provide additional info

Thanks