Dynamic Population With Query Strings Not Functioning

I'm trying to use Query Strings here:
http://10secrets.heliopower.com/secret-1/

This page will only be seen by existing subscribers, so we want the form to auto fill with their data should they want to take the next step with us. We'll already have the name and email, we will want the phone number from them. So we want the name and email to auto-fill from the URL we've sent them in their email.

I've got the dynamic field population setup: http://cl.ly/image/003d2W2p0Q11

But when I try the following:
http://10secrets.heliopower.com/secret-1/?name=Scott&email=SGordon@HelioPower.com
or
http://10secrets.heliopower.com/secret-1/?name=Scott

I get a 404 error.

You Sir... are a genius.

And here I thought I had broken the whole system.

Thanks.

I would suggest adding the info about reserved names to the documentation page for the Query Strings. :)