Sounds stop playing when user locks screen on iOS with AIR 3.9 Beta

We built a simple application that should play sounds when in background and when the screen is locked.

Since we updated to the latest AIR 3.9 Beta SDK, all sounds stop playing when the user locks the screen on iOS.

The sounds resume when the screen is unlocked.

- it works on Android

- we use renderMode : cpu

- we use UIBackgroundModes : audio

- we use NativeApplication.nativeApplication.systemIdleMode=SystemIdleMode.KEEP_AWAKE;

- sounds play when the app is in background

- was working great with AIR 3.8 SDK

Any help would be greatly appreciated.

Thanks!