Hey this might not work,
But when publishing do you publish the iPad 2 version first?
I've read something funny that you have to publish the iPad 1&2 version before you publish the iPad 3 version
not sure why - but that makes the prompt for the right content on the right device!
Hope this helps!
thans for your idea. We solve the problem:
The old V18-app found a folio that works (the iPad2-Version, built with V18 tools), so there's no need to update the app.
We update the iPad2 and the iPad3 folio with V20 tools.
The user gets the information that there's an update for his folio.
When he tries to update his folio, he gets the information that he has to update the app for this update of the folio,
because the V18-app doesn't find any content that can be used, both folios are V20.
Glad you got it all sorted!!