How do I support my iOS 3.1.2 users now that I've upgraded to Xcode 3.2.3?

I recently released a new version of my iPhone app that was built for iOS 3.1.2. Now I want to release a very small bugfix update, but in the time between my last release and now, I've upgraded Xcode to 3.2.3 and upgra开发者_StackOverflow中文版ded my test iPhone to 4.0.

Since these are very simple changes, I want my iOS 3.1.2 users to be able to get these fixes but it looks like Xcode wants me to build for iOS 3.2. That doesn't really go back far enough for me.

I've done some research (mostly around SO) and learned that it's possible to use SDK 3.2 and simply set the Deployment Target to 3.1.2. But if I do that, how can I do a basic sanity check of my app's compatibility with that OS, given that I have a brand new development environment and SDK? My physical hardware is now OS 4, and the iPhone Simulator that ships with Xcode doesn't seem to simulate OS 3.1.2.

Is it possible to get an older version of the SDK to test my code? Do I have any other options?

There isn't a good way to sanity check it. The right solution is to set your base SDK to 4.0, and set your deploy target to 3.1.2. Without a device to test this on though, you're a bit SOL. apple's docs

If you really want to test you app on some 3.1.2 devices before uploading to AppStore, try to find some beta testers from iPhone app discussion forums and send Ad Hoc distribution package to the beta testers.