dbm support broken? Please help!

I'm trying to build php 4.0.4pl1 with dbm support on my RedHat Linux 6.2 box. I need it to be able to work with apache 1.3.14 mod_auth_dbm. Each time I run: ./configure \ --with-zlib=shared \ --with-xml=shared \ --with-gd=shared \ --with-interbase=shared \ --with-db \ --enable-dba=shared \ --with-dbm \ --with-gdbm \ --with-ndbm \ --with-db2 \ --with-imap=shared \ --with-openssl=/usr \ --with-config-file-path=/etc/httpd/conf \ --enable-versioning \ --with-apxs=/usr/sbin/apxs \ --enable-memory-limit \ --enable-trans-sid \ --enable-sysvsem \ --enable-sysvshm \ --enable-gd-imgstrttf \ --enable-track-vars I get the following error: configure: error: cannot find necessary header file(s) If I remove the line "--with-dbm" everything works fine. What should I do or what should I need to build dbm support into php? I need "dbm", since looks like other formats are not compatible with mod_auth_dbm (and ... Yes, dbmmanage works fine). Thanks P.S. I've also tried with php-4.0.5RC1 but the result was still the same.