[0.4.0] No sound if channel audio is mono

Hi all,
I have a problem with mono channels I have no sound, but with stereo it works. I tested with xine and xineliboutput and I get the same result

attached channel that does not work

EuroNews;Globecast:12226:HC34M2O0S0:S19.2E:27500:2432=2:2433=deu@3,2434=eng@3,2435=fra@3,2436=ita@3,2437=esl@3,2438=por@3,2439=rus@3,2440=ara@3,2441=tur@3,2442=per@3:0:0:31220:1:1091:0

what is the problem?

thank for your help.