2.0.2 > 2.0.5 Cannot edit exhisting posts only create new ones

I can’t edit any of my drafts, or edit exhisting published posts. All I get is a preview shot and the sticky tick box. If I click “edit” nothnig happens.

Here’s a screenshot:

http://www.cjgavin.com/beam/zzr-rebuild/problem.jpg

Help! I am going live in a few days and this sort of thing would be a real disaster on a production site.

Have I damaged something?

My upload process was:

Delete all wp folder except wp-content and wpconfig.php
Upload all new 2.0.5 files
Run the updater