cgi and mod_perl-1.26, Apache-1.27, perl-5.8.0, FreeBSD fail with 'The document contained no data'

Hi all,

I am having problems running cgi scripts under mod_perl.  I
realise that this question has been asked before but I have not
been able to find a reference to this particular behaviour in the
manuals or newsgroups.

Problem summary
---------------
Scripts running under mod_perl fail.  Netscape returns the popup

  'The document contained no data'

Nothing is printed in the browser window.  Scripts that use the
mod_perl api work OK.

Example scripts
---------------
The cgi script below fails.

#!/usr/bin/perl -w

print "Content-type: text/plain\n\n";
print "Hello World\n";


The mod_perl api script below works.

my $r = Apache->request;
$r->content_type("text/plain");
$r->send_http_header;
$r->print("Hello World");

Script configuration
--------------------
Alias /perlbin ${TOP}/perlbin
PerlModule Apache::Registry
<Location /perlbin>
  SetHandler perl-script
  Perlhandler Apache::Registry
  Options +ExecCGI
  allow from all
  PerlSendHeader On
</Location>

Machine config
--------------
The cgi script fails on this box:

FreeBSD 4.5-RELEASE-p23
Apache/1.3.27
perl-5.8.0
mod_perl-1.26

The same cgi script with the same script config works fine on
this one:

FreeBSD 4.5-RELEASE-p23
Apache/1.3.20
perl-5.005_03
mod_perl-1.26


It looks as if the CGI script is not returning its stdout to the
browser but I can't for the life of me see why.  Any help would
be very much appreciated.

George Savvides