Try a change of filter ie for better one, as that has been flagged as
issue in past.
This off Plus net forum:
was having the same problem with Caller Display since ADSL was
activated on my line, and I was told by BT that it's not supported.
However, I saw an article on ADSL Guide (
www.adslguide.org.uk) last
week about a 'professional' microfilter which is supposed to work with
Caller Display. It's sold by ADSL Nation
(
www.adslnation.com/products/xf-1e.php) and they offer (at the moment)
a 30 day money back guarantee if it doesn't work. I got mine today and
it works ! You don't need to replace all your microfilters, only those
which have phones plugged into them whose Caller Display isn't working.
If you buy one, I suggest that you tell the forum whether it solves the
problem - maybe PlusNet should be informed of this