Configure line for Apache module:
'./configure' '--with-apxs=/opt/IBMHTTPServer/bin/apxs' '--enable-force-cgi-redirect' '--enable-discard-path' '--enable-debug' '--with-config-file-path=/etc' '--with-pear' '--with-openssl' '--enable-magic-quotes' '--disable-short-tags' '--with-zlib' '--enable-bcmath' '--with-bz2' '--enable-calendar' '--with-curl' '--with-gdbm' '--with-ndmb' '--with-dom' '--enable-exif' '--enable-ftp' '--with-gettext' '--with-gmp' '--with-imap' '--with-imap-ssl' '--with-kerberos' '--with-mcal=../libmcal' '--with-mhash' '--with-ldap=/home/joem/php/ldap' '--enable-shmop' '--with-snmp' '--enable-ucd-snmp-hack' '--enable-sockets' '--with-regex=system' '--enable-sysvsem' '--enable-sysvshm' '--enable-tokenizer' '--enable-wddx' '--enable-yp' '--enable-inline-optimization' '--enable-memory-limit' '--enable-sigchild' '--with-mysql=/home/joem/php/mysql'

Script:
<snip>
 $file = getCurrentFilename($product, $platform);
  if ($file != FALSE ) {
    $fp = fopen("../../../software/$file", 'rb');
    rewind($fp);
    header("Cache-control: private"); // another fix for IE
    header("Content-Type: application/x-stuffit");
    header("Content-Length: ".filesize("../../../software/$file"));
    header("Content-Disposition: attachment\; filename=\"$file\"");
    header("Connection: close");
    $fr = fpassthru($fp);
</snip>

fpassthru() seems to be wonky.  I'm trying to send .sit archives through this script.  The files are sent ok if they are ~300KB.  Other files that I need to send that are ~3.3MB fail.  IE reports a DNS error (bogus) and Galeon (Mozilla) reports File Contains no data.   PHP is running as an apache module in IBM HTTP Server 1.3.19.3 (Apache 1.3.20).  There is no core, and no error reported in httpd's error log.  The transfer log reports a 200 code for success.

Backtrace:
I don't get a SIGSEGV...