Catalogue name: maemo.org
Web address: http://repository.maemo.org/extras
Distribution: fremantle-1.2
Components: free non-free

That is the one that has been automatically updated on the update to 1.2. I have now deleted my extras-devel catalogue until someone can tell us the settings for it!! Totally over my head, I'm afraid.

* Update *

I have just added the extras-devel catalogue, and the settings I have used for that is...
Catalogue name: maemo.org extras-devel
Web address: http://repository.maemo.org/extras-devel
Distribution: fremantle
Components: free non-free

I hope that helps you all. I have read on various sites that some people have had to refresh a few times, different people getting different errors, but the main one is a 404.