Can Iphone 4S and Bose Sounddock II get married again?!

My Iphone 4s can no longer play music on my great Bose Sounddock II.

I searched a lot already, and visited 2 retailers, but no solution yet.

I can charge, but cant play music anymore.

It worked fine a couple of IOS-updates ago, but no longer. Now I run IOS 7.1

But my wifes Iphone4 is still doing great on the Bose Sounddock II, and she runs the newest IOS7.1 also....

Can they get married again?! (Iphone 4s and Bose SoundDock II)

All suggestions and answers are really appreciated!

Thx. in advance!!