PN profile dropping over the Xmas period- why?

[#1]

Seasons greetings folks,
my speed has been dropping from around 2M (yes that's correct 2Meg- but as you can see it is a long line - about 6.9km) over the Xmas period and is now
my PN profile is stuck at 1.5. In did a couple of "graceful disconnects" before Xmas to replace a RJ11 modem cable
with a cat5 modem cable. Only other change has involved our BT OR /Contractors installing a fibre cabinet and replacing
the existing PCP cabinet (not sufficient space inside old cabinet I think) which serves my line. The fibre cabinet has not yet
been commissioned (apparently BIS date 31/12/2014  ::)).
Downstream line usually runs at 3db
BT quiet line test = no noise and current modem stats look like this :-
System Up Time 5 days 19:47:08
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN pppoa 4497273 7674711 0 2449 6936 3 days 13:37:06
LAN1 Link Down 1851203 1250469 0 4048 342 --
LAN2 Link Down --
LAN3 10M/100M 5 days 19:47:08
LAN4 Link Down --
WLAN 300M 8070169 5074606 0 4983 1842 5 days 19:46:43
ADSL Link Downstream Upstream
Connection Speed 1799 kbps 667 kbps
Line Attenuation 63.0 db 38.2 db
Noise Margin 6.9 db 5.4 db
I cant seem to get the BT speed tester to run, but would appreciate any chance of checking
the line and nudging profile up.
Ian

[#2]

The line looks pretty stable, good uptime and very few errors showing. I'm therefore going to SNR reset your line back to a 3db target, this should happen within the next few hours and will retrain your line starting at the 3db margin.

[#3]

Hi Chris,
many thanks your SNR reset appears to have worked 
see current modem stats below :-
System Up Time 6 days 00:01:29
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN pppoa 4289671161 4286272983 0 761537 242675 01:16:23
LAN1 Link Down 1868491 1264817 0 3936 334 --
LAN2 Link Down --
LAN3 10M/100M 6 days 00:01:29
LAN4 Link Down --
WLAN 300M 8134561 5155750 0 4915 1917 6 days 00:01:04
ADSL Link Downstream Upstream
Connection Speed 2407 kbps 680 kbps
Line Attenuation 62.5 db 38.0 db
Noise Margin 2.9 db 6.8 db
will keep an eye on the line for the next few days,
Ian

[#4]

No problem. I've just upped the profile on our side to 2100 so that's not causing any issues too.