There is a general problem with navigation voice prompts being played at an inaudible level when another media app is playing over bluetooth or even line-out (aux) connection. The latest gingerbread music app works fine, but XiiaLive and others (winamp) do not play nicely with navigation voice prompts. The music volume gets lowered, but the navigation voice prompt is so low that it cannot be understood. Since the latest gingerbread music app doesn't suffer from this issue any more, I thought maybe XiiaLive could also implement a similar fix.
More about this issue can be found here:
Customer support service by UserEcho