I've had a problem which sounds similar, but I'm not sure whether it's a problem with the game or just me missing something obvious....
I've completed the final objective in the first city (Berlin) in campaign mode. I receive the message confirming that I've completed it, and I click 'finish' in the message. This then takes me back to the game's main menu.
From there, how do it get to the next city?
If I go to 'New Game' and 'Campaign' mode, it still has just the one option which starts me back at the beginning of Berlin. If I go to 'Scenarios' only Berlin is available still. There is nothing I can see in any of the options which is different to when I first bought the game.
I've never had a demo or Beta on the computer, so it can't be that. I could try removing and re-installing the game of course, but presumably that would mean I had to do the whole Berlin scenario again from scratch (pretty boring when I've done it already), and with no guarantee that when I'd done it the result would be any different.
Any help much appreciated...