phone calls through 30-pin dock audio out?

[V4705]

hi, i'm using procable by radtech to connect audio and power with the same cable, the problem is the iphone doesn't play phonecalls through 30-pin audio out like this cable and like dock stations/speaker systems.

there is any hack to make this work (on 3g, jailbroken, 3.1.2) ?

thanks!

 

[V4705]

anyone?
thanks.

 

[sjdigital]

I looked into this a few months back when trying to find a way to hook my iPhone up to my car audio system and reckoned routing phone calls through the dock connector would save having to hook up a bluetooth kit. But everything I read said that it couldn't be done and suggested that it was a hardware rather than a software issue so no jailbreak hack could fix it.