I have an ipod touch (second generation) and have recently got speakers however they dont charge the ipod at the same time. I get a message that this application is not supported. Is it just the make of speakers (jbl) which I have? or is this a common problem with this ipod? I know I can charge the ipod via a usb cable but just dont understand why it wont charge through the docker/ loudspeakers? Is there any easy fix to this?