how to test on xcode ios 4.2.1?

I have previously downloaded xcode 3.2.5 and开发者_开发技巧 I see i have iphone sdk 4.2 i uploaded my app to appstore and they told me back it crashes on sdk 4.2.1 however I could not find yet a way to test it on 4.2.1 on my mac with xcode... i saw on apple site either 3.2.5 with sdk 4.2 or sdk 4.3beta how can I test then with my mac on sdk 4.2.1 please?

thanks

iOS SDK 4.2 covers 4.2.1. So you're already testing it for 4.2.1 as well as you can on your Mac. The only real way to fully test your app with "iOS 4.2.1" is on a real device.

If you read the support page for iOS 4.2 (http://support.apple.com/kb/DL1061) it seems iOS 4.2 and 4.2.1 are essentially the same, as at the bottom of the page it states:

Note: iOS 4.2.1 is the version number displayed in the iOS user interface and iTunes.