Adobe AIR, IOS emulator: selecting the correct device

Hello,

I'm really new to xcode and Mac, so I really need help on this:
Using Apache Flex with air 4 I can debug ios applications with any target device. All I have to do is keeping open xcode and the device target I want (ipad, ipad retina etc)
If I use Apache flex with Air 14 the iOS simulator restarts and I end up always with the smallest iphone 4.

Why this happens and how can I fix this behaviour?

Using xcode 5 on Mavericks, latest intellijdea.

Thanks for your help

Alfonso