I cannot conquer anymore !

Hi everyone !
I'm new on AtWar and i absolutely love this game. But since 2 hours, i can't play correctly because of a big problem which prevents me from playing..
So here's a video of my problem, because i'm not really good to explain in english, i'm italian, so i made a little video !

http://www.youtube.com/watch?v=n9kKTp4NoQ0

As you can see, i can't conquer any country.. So in the game, it's a little bit problematic, you know.
Can you help me ? Did you have this problem in the past ? I really want to play again.

Thank you !

After retry & retry, i realise that i can't conquer with all type of planes.
By boat or in walking, it works but not in flying.

Planes dont conquer countries. You need land units. Bombers just weaken things to make it easier. But you need to send land units in order to take things over.

Oh Ok, thank's for your fast answer !