How to find deprecated functions in xcode 3.2.5?

I have developed a iPhone开发者_StackOverflow社区/iPad project in XCode 3.2.5 version. I is working fine in 3Gs and above version devices. But, a single screen is not working(App Crashes) in 3G mobile. How to find the problem? It means, i think i was used some deprecated functions in my code, it may not supported in 3G mobile? How to find the solution? Can any one please help me? I was used below things in my code; NSString, NSDate, NSDateFormatter, UIScrollView, UILabel, NSMutableArray and NSMutableDictionary. These are the things i have used in that class. I can't find which one is not supporting? Please help me to solve this problem.

Thanks.

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API changes:

1. 3.0 -> 3.1
2. 3.1 -> 3.2
3. 3.2 -> 4.0
4. 4.0 -> 4.1
5. 4.1 -> 4.2
6. 4.2 -> 4.3