Why not send the real Refresh header instead of using the META tag.

print header(-Refresh => "5;url=http://someurl//thiscode.pl");
[download]

Or if you really want to do it in a META tag then try the following:

print start_html(-head=>meta({-http_equiv => 'Refresh', -content=> '5;
+ URL=http://someurl//thiscode.pl'}));
[download]

Or if you are paranoid, do them both :)