iPhone app does not run on old device (3G, 3GS, ...) [duplicate]

Question

Possible Duplicate:
Is it possible to target older iOS versions when using Xcode 4.2 and iOS 5 SDK?

I have developed an app which works on iPhone 4 (iOS 4.3 & 5) (which used during developing). Now I have tried to test on 3GS (iOS 4.3.3) and 3G(iOS 4.2). But app does not load into these devices. I can see following messages on consol when try to deploy to device.

Sat Jan  1 17:27:38 unknown lockdownd[16] <Error>: 2ff68000 handle_connection: 
            Could not receive USB message #6 from Xcode. Killing connection 
Sat Jan  1 17:27:38 unknown com.apple.mobile.lockdown[16] <Notice>: Could not 
            receive size of message

I have tested on Xcode 4.0.2 as well as 4.2 beta. Restarted devices and MAC but still same. Can anybody know about this issue? Thanks

Answer 1

This can come for various reasons. Until now this is are the cases pople have encountered:

• bad cable -> try another one, or hold it really still when programming
• unsuported features mentioned in info.plist -> check plist
• unsuported architecture (by default Xcode4.2 uses standard arch= armv7 ) -> add armv6

Answer 2

Check your cable or your device dock. The problem in your console says your material connection is not healthy. Can you perform an itunes synchronization ?