Problem publishing old iOS app

Hi,

I have an old iPhone app on the AppStore published with the IPA publisher in Flash Pro CS5 (targeting iOS 3.0).

I now need to update this app, but have run into problems getting the Application Loader to accept my IPA-file.

The error message I get is:

"This bundle is invalid. Apple is not currently accepting applications built with this version of the SDK or Xcode."

Any ideas how to solve this?

Thanks