Having it crash on a device you can access should be massively helpful as you can check the logs on that device. You might do so and post what you find.
As for a release build crashing but a debug build working that is not at all uncommon. A debug build might e.g. be doing initialisation which is optimised away in a release build. Or it might be handling errors which are left to run in a release build to cause havoc. This could be in your code or in AIR's libraries. Again check the logs for pointers to where it is crashing.