httpd.conf:

# LoadModule foo_module modules/mod_foo.so
LoadModule php5_module          modules/libphp5.so
LoadModule mod_rewrite          modules/mod_rewrite.so
#
#AddModule mod_rewrite.c

~~~~~~~~~~
Note that I get same error with our without the "AddModule mod_rewrite.c"
~~~~~~~~~~

bzitzow$ ls -al modules | grep mod_rewrite
-rw-r--r--    1 root  admin    118336 Jun  5 17:19 mod_rewrite.so

bzitzow$ /www/bin/httpd -k start
httpd: Syntax error on line 54 of /www/conf/httpd.conf: Can't locate API module structure `mod_rewrite' in file /www/modules/mod_rewrite.so: undefined symbol

UPDATE - ALL .SO files in modules directory:
bzitzow$ ls -l modules/*so
-rwxr-xr-x   1 root  admin  13574968 May 13 02:26 modules/libphp5.so
-rw-r--r--   1 root  admin    118336 Jun  5 17:19 modules/mod_rewrite.so

I obtained the mod_rewrite.so from a different directory:
bzitzow$ cp /opt/apache2/modules/mod_rewrite.so mod_rewrite.so

UPDATE 2
!!!!!!!!!!

bzitzow$ locate libphp5.so
/opt/zimbra/httpd-2.0.54/modules/libphp5.so
/sw/src/php-5.2.1/libs/libphp5.so
/sw/src/php-5.2.2/libs/libphp5.so
/usr/local/php5/libphp5.so
/www/modules/libphp5.so

bzitzow$ locate mod_rewrite.so
/apps/sugarcrm/apache2/modules/mod_rewrite.so
/opt/apache2/modules/mod_rewrite.so
/usr/libexec/httpd/mod_rewrite.so