Error while using AIR 2.7 in Mobile applicaton

hi,

I am creating a application for mobile but when i am trying to change the AIR version from 2.6 to 2.7. It show me the error while compiling the application.

Process terminated unexpectedly.

invalid application descriptor: Unknown namespace: http://ns.adobe.com/air/application/2.7

Launch command details:  "C:\Program Files (x86)\Adobe\Adobe Flash Builder 4.5\sdks\4.5.1\bin\adl.exe" -runtime "C:\Program Files (x86)\Adobe\Adobe Flash Builder 4.5\sdks\4.5.1\runtimes\air\win" -profile mobileDevice -screensize 600x986:600x1024 -XscreenDPI 168 -XversionPlatform AND D:\WSFlexPremium4.5\VCCheckMobile\bin-debug\VCCheckMobile-app.xml D:\WSFlexPremium4.5\VCCheckMobile\bin-debug

i tried out all help avaliable but not succeed to resolve the problem.

Please help