Perl CGI, IIS and other unholy unions

mush4brains has asked for the wisdom of the Perl Monks concerning the following question:

I'm getting an apparent error in a Perl CGI script I'm running from IIS. The code:

    print '<!DOCTYPE html>
    <html>
    <body>
    ';

    print "1<br>";
    print "2<br>";
    print "3<br>", "4<br>";
    print "5<br>". "6<br>";
    print "</body></html>"
[download]

This gives the result, in the browser (IE):

1
2
3
5
6
[download]

Note that the "4" is missing -- the comma-delimited arg's to the 4th print apparently aren't working here.
This IIS server is running ActiveState Perl "5.006001" (from $]).

If I run this script from browser on a different IIS box with ActiveState Perl 5.006, the 4 is *not* missing, so the comma apparently "works".
And... If I run this script from command line on yet another box with AS Perl 5.006001, the 4 is *not* missing, again.

Actually, I suspect this has nothing to do with IIS/CGI/etc., but rather something to do with print and commas. I've searched the web, perldelta, PerlMonks, but I'm not sure exactly what I should be searching for...
Anyone got an idea? (I'm willing to accept I made a dumb mistake.)

TIA, oh Mighty Monks.

Signed,
Mush4brains

Back to Seekers of Perl Wisdom