Gentlefolk,
I've just tried two different lines, one tolerable and the other lousy and they both produce a test error afer accepting the phone number pop-up in the BT speedtester.
TBB speeds:-
Line 1 down 938.43 kbps up 351.81 kbps
Line 2 down 232.86 kbps up 365.54 kbps
Kind regards,
Walter