That's correct - they use the same connector on the back of the radio. As such if you have the sat nav (or an external CD changer) you need the Y cable to act as a splitter; otherwise you can just plug it into the connector directly.I thought so, the guy said the connector from xcarlink that goes into the back of the cd player, is the same as one side of the Y cable, hence it wasn't needed.
Sounds to me like one end of the cable isn't quite seating correctly, and you moving the device causes it to shift and make a proper connection.
Check that your dock connector isn't full of lint (as that's usually my problem). Then make sure the cable is properly connected.
If you're still having problems it may be the unit that hasn't had the connection internally joined correctly - get in touch with xcarlink for that.