Problem with phone ring on internet calling

[freel07]

We have recently been moved over to a Sky SR203 hub with internet calling. I have connected our existing telephone instrument to the hub via Phone UK socket ok and the phone calls out and will accept incoming calls ok. However if the call is terminated by the caller before we answer it the instrument continues to ring untill we pick up. Additionally the calling party ID is shown twice on the display.  I have tried two differnt instruments and both show the same problem. Has anyone else had similar problems?