The reason it looks perfect when you preview in LAN is because your game is not packaged yet, and it is running directly off of C2 in your devices browser. It is like having a personal server for your device so what you see on your computer you will see on your device. This is also why sound works so well when previewing in LAN.
I think you will end up with the same result with phonegap as your getting with appMobi except you wont have sound.
It is strange though how your game seems to repeat itself like that. Most people just get a white, or blank edge to the right side of there games.
The only way I have found to fix this so far is to build your game to the exact screen size of each device. I know a lot of work but if you made a game like the ghost shooter game where your game is very large, and you didn't need a certain playing area to always be visible you wouldn't have this problem. I could be wrong on all of this but if there is another way no one is sharing there secret.
Here is a post I made when I was trying to figure this all out maybe it will help: