I saw a posting a while ago that suggested you can't play sound from your application while in a data call, and testing the built-in sound player application seems to bear this out (you get a message saying as much).
The question is, is this just a limitation of the sound player app or a more general restriction?
I want to stream audio from the internet (ie. during a data call) - this will obviously be difficult if the user has to disconnect before they can listen to it!
The feature you would like to implement is only enabled in Nokia Communicator 9210i/9290/9210c. This means that you can play audio file, stream audio from the Internet during a data call. The restriction is on the hardware that the previous model N9210 does not support this feature and so it cannot be upgraded either by any software.