My xcode is 4.2.5. I don’t want to upgrade xcode now, because I read that xcode 4.3.2 has some problems.
I know it is necessary to upgrade xcode to test on 5.1 devices, but I am just wondering whether a release version compiled by sdk 5.0 can run on 5.1 devices.
You will not be able to build to a device running 5.1 without upgrading to the latest version of XCode (which also requires OSX Lion).
If you were to submit your app to the app store, however, users running 5.1 would still be able to download it. It very well might crash if you have 5.1-specific errors in the code, but users could install it.