Your reference specifically helped... http://honglus.blogspot.com/2010/08/resolving-perl-cgi-buffering-issue.html. Now, the code works as I expect (see below). I guess this is normal behavior and something was screwed up on my RHEL 4 server... hm. Also, since i'm doing my own "buffer management", I removed the $|=1; line.

#!/usr/bin/perl -W

use strict;
my $r = shift;
print "Content-type: text/html\n\n";

for (my $x=1; $x<=10; $x++) {
    print($x);
    sleep 1;
    $r->rflush;
}

exit(0);
[download]

Thank you!