Download better again!

[#1]

After 3.5 nudging to 4 megs download about 10 days ago, it all fell back. At that time PN & BT IP profiles showed 4000.  Ticket open [ID: 31200280] & no complaint with the tech. guys.  Situation seems to be improving:-
- I'm told that intermittent disconnections is my prob, although I was not aware of any.
- interleaving will be switched on [IS IT?]
- my SNR starts the day high [16] gradually drops through the day to 8/9
- this morning BT speedtester is back to IP profile 4000; had dropped back to 2500 earlier in the week
- PN is showing 3000
- D'loads @ present show BT 2.6, Speedtest 2.68, My b'band 2.68 Mb/s
Can someone please nudge the PN line speed and can anything be done about my SNR - hopefully stability & joy will be the Christmas present from PN
Many thanks, Ian

[#2]

Hi Ian,
I've updated that for you now, here's hoping it either stays stable or improves for you.

[#3]

Matt, thank you for such a speedy response. Much appreciated - I'll await & see.
Ian

[#4]

For information, downloads have shot up significantly and indicate 3.2, 3.5 & 3.8 Mb/s using three different sources.
Grateful.

[#5]

Good to hear, hope it stays like that now.

[#6]

Well, no it unfortunately stayed like that for 12 hrs and is now back down to 2.5 or less, from 3.5 downloads.  Conversely BT IP is back to 3000 from 4000.  I see Support's interleaving has tripped in, following their comment 'very high number of disconnections' & 'your connection is quite erratic'.
Q. both [desk & l'top] our computers are in use throughout the day, line connection to modem/router is direct to master BT & we have not disconnected.  So, what could be causing the disconnections?  A minefield, I suspect!

[#7]

Just an update on my 'very high disconnections' problem, which persistently has affected stability and download speeds. 
Good help from Tech Support.  Faulty modem/router identified - now replaced my Belkin N+ modem/router [new earlier in July] with the PN Thomson.  Hey presto, PN tell me connection stability OK.  Will now await to see now how down/loads improve & stabilise. 
Lesson for me, don't place one's faith in bits of kit, even if they are new!