Finally got my copy registered with Impulse.  All seems a bit complex/slow/fraught to me, but I'll have to live with whatever they decide they want for their copy protection.

I do have a question.  Sorry if it's been answered before.  I believe I am right in saying my serial number has been registered against my email address, and cannot be changed once registered or transferred to anyone else.  Fair enough to stop copying, but over time I may well change my email address.  Could someone explain what happens in that case, please?  Thanks.