Hello,
I think there is now an other version at the server. It´s  version 3.8  and it works. You can later upgrade to 3.9, too.
But Matrix didn't say anthing to me.

Maybe this helps you.

Hello,

I have the same problem. I'd buy Harpoon on 03/31/08. But, it still doesn't run because of an invalid serial number.
Could I please also contact you Erik.

Thanks