Help XPERIA C3 DUAL WALKMAN ISSUE

[varunmar]

I have bought the xperia c3 dual. My walkman app stops automatically,whenever i switch to another app from walkman. or in other words i cannot play music in background.suppose iam listening music and i switch to whats app or facebook app,the walkman stops playing and the phone automatically closes the walkman app.I have to re-open walkman and play again songs,simply if i want to listen songs i have to stay inside walkman app.I think its a RAM Related issue and i havenot installed any task killer or memory booster.Even 256MB Ram phones doesnot stop music player even if the RAM Is full,But C3 has 1Gb ram and why it kills the music player.I tried other music players from playstore.still no use,Iam using the updated version,and also tried by un-installing the update,the problem still exists.No response from sony.
Thanks