Apache 1.3.12 DSO with optimization and 1.3.20 static
with debug. 4.0.4pl1 doesn't have this problem.
PostgreSQL 7.0.2 from ports. MySQL 3.22.32 from ports.
PHP configure line:
./configure --with-apache=... \
--with-config-file-path=/usr/local/etc \
--enable-safe-mode \
--enable-calendar \
--with-mysql=/usr/local \
--with-pgsql=/usr/local \
--with-mm \
--with-system-regex \
--enable-debug \
--enable-track-vars \
--with-pdflib \
--with-ttf \
--with-imap=../imap \
--with-gd=../gd
php.ini is pretty generic, changes are related to safe_mode
and other security stuff.

User enter email address to register. Apache succefully
process the request, output valid page, and then segfaults.
The web site is http://www.chrysler.lv/
I've put all related php files and gdb session at
http://kvin.lv/arkadi/tmp/php-pgsql-pr.tgz
Here is the script that cause segfault:

<?php
include('setphp.php3');
$local_connection=mysql_pconnect($mysql_db_host,
$mysql_db_user, $mysql_db_pswd);
mysql_select_db($mysql_db_name, $local_connection);
$email_str='
0123456789abcdefghijklmnopqrstuvwyxzABCDEFGHIJKLMNOPQRSTUVWYXZ_-@.';
$form_process=1;
if($reg_email==''){
    $form_process=0;
    $err_str ='<font class="font1">J<FB>su e-pasta adres<E7>
ir k<EF><FB>da. L<FB>dzu
izlabojiet to un re<EC>istr<E7>jieties v<E7>lreiz.</font>';
}
if(strpos($reg_email,'@')<=0){
   $form_process=0;
   $err_str ='<font class="font1">J<FB>su e-pasta adres<E7>
ir k<EF><FB>da. L<FB>dzu
izlabojiet to un re<EC>istr<E7>jieties v<E7>lreiz.</font>';
}
if(strpos($reg_email,'.')<=0){
   $form_process=0;
   $err_str ='<font class="font1">J<FB>su e-pasta adres<E7>
ir k<EF><FB>da. L<FB>dzu
izlabojiet to un re<EC>istr<E7>jieties v<E7>lreiz.</font>';
}
for($i=0; $i<strlen($reg_email); $i++){
    
if(strpos($email_str,substr($reg_email,$i,1))<=0){$form_process=0;
        $err_str ='<font class="font1">J<FB>su e-pasta
adres<E7> ir k<EF><FB>da. L<FB>dzu
izlabojiet to un re<EC>istr<E7>jieties v<E7>lreiz.</font>';
        break;
     }
}
if($form_process==1){
        $reg_ip=$REMOTE_ADDR;
        $reg_host=$REMOTE_HOST;
        $mys=mysql_query("insert into reg_emails
                        (email, reg_time, reg_ip,
reg_host,site_id) values
                        ('$reg_email', NOW(), '$reg_ip',
'$reg_host', '$site_id')");
        $err=mysql_error();
        if(isset($err) && $err!=''){$err_str.='<font
class="font1">J<FB>su
e-pasta adres<E7> ir k<EF><FB>da. L<FB>dzu izlabojiet to un
re<EC>istr<E7>jieties v<E7>lreiz.</font>'; }
}
if($err_str!=''){$reg_email_answer=$err_str;}
else{$reg_email_answer='<font class="font1">Paldies! J<FB>s
esat re<EC>istr<E7>jies.</font>';}
include('index.phtml');
?>

It use setphp.php3 that define db/passwd/site_id. It is
called from site main index.phtml.