Would suggest to me that it's a poor line. Like I said before with an SNR below 10 the router has a hard time to keep the line connected. Try the router in the master socket and see if the snr improves. If it's in the socket behind the facia on the master socket this should disable all other extensions iirc but I would disconnect any phones, sky boxes etc. Your isp should be able see the router from their end and do a basic test but they will probly recommend you bet a BT line test done.
Sorry chap, i forgot your reply and didnt re-read my thread, thanks for that
So my router is doing damn well being connected at a 7...........