Well I'm mystified on this one, trouble is I've not been invited round to have a look myself!
Quiet line test was good I'm told. Sam's checker gave very optimistic line length (see earlier post) - it looks more like 1km minimum on a map, so could be up to 1.5 or so actual.
Thus, maybe the down attenuation of 25db is reasonable, it drops a little when connected to master socket, to 23db. Noise margin looks fine around 14 or 15 db.
Wherever the router is connected, the connection is lost after a while (half hour max).
I think it may be a faulty router and I can't find another to borrow. They'll have to get BT to supply another.
One other thing, could a new satellite dish next door cause problems?
Terry.