Despite iPhone Base SDK set to 3.1, App Store lists app as needing OS 2.2

A follow-up (sort of) to this question: in the Xcode build tab, I set my Base SDK to 3.1 but after uploading to the App Store, I see it being listed as requiring 2.2 or later. Why is开发者_高级运维 that?

Both Base SDK and Deployment Target are set to 3.1.

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In Xcode, there is a different set of Base SDK and Deployment target values for the project, than for the Target. My project had the correct values set, but the Target had 2.2 set for Deployment Target.

I'm not sure yet what the Deployment Target in the Build settings for the Project is supposed to do, but the Deployment Target for the Target is what gets used by the iTunes App Store.