Hi. We originally planned to publish the Avastar and Primstar addons
for Blender 2.63 just in time. But unfortunately some recent changes
in blender stopped our addons to work.
We have fixed the issues yesterday and are now testing the addons again.
That will probably take a couple of days.
Please be aware of that if you plan to upgrade to Blender 2.63.
I will notify you as soon as the new Primstar/Avastar updates
are ready for publishing.