Registration Activation error (20)

We are running Autocad 2004 and purchased the upgrade to 2005 and joined the subscription program before 2006 came out so we wouldn't have to pay for
being 2 steps behind. The 2005 packages came and a couple weeks later a 2006 disk came. The number matches the subscription, but I can't activate. I get a Registration activation error (20). Can't find what that means. Anyone know? Thanks, -S
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.