Unable to edit Acceptance tab in Story editor

I am having a problem with acceptance tests after moving a project from the SCRUM template in RTC 1 to RTC 2.0.

It seems that all the old user stories that existed before the migration have a Custom tab in the story editor (in Eclipse) that contain the acceptance tests. In the web client the tab doesn't exist.

When I try and edit the Acceptance tab I have a blank page and I cannot add any details (this is true for both the Eclipse client and the web client).

It does work correctly if I create a new story: the Acceptance tab has an editable field into which I can add my acceptance criteria.

So did I do something wrong when migrating from RTC 1 to RTC 2? Or did I do something wrong when picking up the new SCRUM template from RTC 2 (I used the instructions here: https://jazz.net/wiki/bin/view/Main/ProcessUpdateForExistingProjectAreas).

Does anyone know how I can get my acceptance tests back into a place where I can see them in the web client?

Thanks, Colin.