First of all, I believe you forgot to increment the data your pulling from the database for the comma delimited file...

        $_file2dl = Format_Date_For_Viewing($_t1->{d},"mysql_timestamp
+_view") . q~,~ . $_t1->{USERNAME} . q~,~ . "$_t1->{FirstName} $_t1->{
+LastName}" . q~,~ . $_t1->{Phone} . q~,~ . $_state . q~,~ . $_num_ref
+erred . "\n";
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Try this:

        $_file2dl .= Format_Date_For_Viewing($_t1->{d},"mysql_timestam
+p_view") . q~,~ . $_t1->{USERNAME} . q~,~ . "$_t1->{FirstName} $_t1->
+{LastName}" . q~,~ . $_t1->{Phone} . q~,~ . $_state . q~,~ . $_num_re
+ferred . "\n";
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Next, try this:
From:

    my $type='text';
    my $_format = 'text/csv';

    my $file2 = "heavy_hitters.csv";
    print header(-type => $_format, -Content_disposition => qq(attachm
+ent; filename=$file2));
    print $_file2dl;
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To:

    my $file2 = "heavy_hitters.csv";
    print header(-type => "text/csv",
-Content_disposition => qq(attachment; filename=$file2));
    print $_file2dl;
    exit;
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That _Should_ work.