Scale Mode doesn't fit my device's screen

Hi,
I've created a mobile game with 320x480 base screen resolution, and i've imported all tiles and actor at 4x (for scale to HD display), but when I have tested my game on my device (720x1280) games is create in left corner, with no full screen stretch or fit to my width resolution. I have tested stretch to fit and scale to fit too, without success (my screen have too much black screen).

What can I do ? Where can I look for resolve my problem ?

Thank you

P.S.: i have already read this topic  http://www.stencyl.com/help/view/mobile-app-scaling/

I think I'm having the same problem as you. I put my display settings as Width: 480  Height: 320. The attachment below shows that the game screen doesn't fit the whole phone screen (Scale to Fit - Full Screen). Does the display settings width size need to be increased?