{AppToMarket} Apk signature make display size problem on tablet

I tried to use App To Market and I executed all steps from Key generation by decompile, generating new apk and sign it an all these steps have been succeded...

Then, when I install my application on my tablet, the original size of the screen, shown here :
 

becomes very small as shown there :

Note that the application seems work well despite this micro size... The application needs a very large screen (10 inches min) to be usable. 

Then I tried version 3.2 and 4.0 of the app to market software and some tests with Inventor 1 and 2, and got the same result. I tried to edit the   <supports-screens android: parameter without any success ! 

I'm a bit desapointed ! Is someone to help me to found the good solution ?