I like it so much that after playing through the first three campaigns on my iPad, I immediately bought the next three through the in-app purchase.
I started the Blitzkrieg campaign and played through the first two missions. Then I bought a shiny new iPad 3 and was looking forward to continue with the new graphical update.
But now I can't access my savegames and what's worse, the three campaigns that I bought, and I'm asked if I want to purchase them when I try to play them.
Apparently my in-app purchases got lost somewhere.

Everything else transfered perfectly via iCloud from my old iPad (updated ten minutes before I bough the new one) and I'm on the same Gamecenter account.
How do I get the campaigns I bought on my new iPad?