I've upgraded to 2.1 and am using the cmd to build a native IOS app but the build fails with:

Code:
sencha package build -p ./packager.json 
Sencha Cmd v3.0.0.250
[ERR]        
codesign_allocate: object: /webroot/[abc]/sencha_2.1/converted/build///[myapp].app/stbuild_template malformed object (unknown load command 34)
../build///[myapp].app: object file format invalid or unsuitable
The application was successfully packaged
Failed to execute system command while signing application with error 256
Failed to package application


[ERR]        stbuild exited with non-zero code : 6
If I set the platform to iOSSimulator the build works and runs the simulator ok.

I'm running on OSX.

Here's my package.json:

Code:
{
    
    "applicationName":"[myapp]",
    "applicationId":"com.[my company].[myapp]",
    "versionString":"1.2.0",
         "provisionProfile": "/[my path]/provisioning_profiles/[myapp].mobileprovision",
        "minOSVersion":"5.0",
        "bundleSeedId":"[my bundle seed]",
"icon": {
                "57": "resources/icons/Icon.png",
                "72": "resources/icons/Icon~ipad.png",
                "114": "resources/icons/Icon@2x.png",
                "144": "resources/icons/Icon~ipad@2x.png"
                },
    "inputPath":"./",
    "outputPath":"../build/",
    "configuration":"Release",
    "platform":"iOS",
    "deviceType":"Universal",
    "certificatePath":"../../../certificate/Certificates.p12",
    "certificateAlias":"iPhone Distribution: [my company]",
    "sdkPath":"/development/android-sdk-macosx",
    "androidAPILevel":"15",
    "orientations": [
        "portrait",
        "portraitUpsideDown"
    ]
      
}
Has anyone seen this or got any suggestions?

Thanks
Matt