Airplay stops working after a call

I am listening to music using AirPlay from my iPhone 5, iOS7.02, thru an AirPort express latest generation.

If I receive a call, music stops (expected). After finishing the call, there is no sound from the AirPort Express. Music should come back out of my APE.

The iPhone shows the correct connection and music playing back.

The only solution I have found is to disable WiFi and close the Music app in the iPhone. Then re-enable WiFi, open music and it starts working again.

I checked the software version of APE in it is the latest.

Any ideas?