Currently I'm using Xcode 4 with 4.3 Base SDK where I'm testing my apps on my iPhone 4.3.3 without any problem.
The problem is when I want to test on iPhone 4.2.1, it's throwing the error "CodeSign Error", and when I googled I found the solution is to change the Base SDK to match the device targeted for testing but couldn't figure out how to change the Xcode setting!
Please help on how to add an old Base SDK in Xcode 4.
Regards