Interleaving in itself will not make any difference, though it can affect error rates.

You need to monitor noise margin and preferably also error rates 24/7.

What router is it, to save me searching your posts?

I am afraid that BT Wholesale will not accept any faults in regards to SNR. They will not manually reset the SNR as it could interfere with the RAMBo Dynamic Line Management that handles your IP profile and the SNR.

compare and contrast :-

"21/10/2009 10:19:27 name 15 - SNR Recalculation initiated which will enable the line to reach optimum speed, stabilisation retrains can be expected over the next couple of days. MSR FTR values will be updated on BBCR by 28/10/2009 16:58:51

15 - OR38 - Uplift to network from exchange to NTE5 for Broadband use"

this ticket followed a voice fault when the DSL didn't come back up (long line) so we had it retrain in case the SNR was hiked up and inhibiting connection. Turned out it was a different issue with the router.

The food chain is too long really, you -> Reseller -> ISP -> BT Wholesale and each link has variable quality individuals, where "it can't be done" is often simpler than "I don't know how to do that" or "I can't find the person that knows" or "I'm not prepared to kick up a fuss until this is resolved".

I see in your ISP notes you mention your Target is 12db but in this thread it's 15db - is that a typo or have things got worse which would indicate the line is still having problems?

Not sure about the interleaving/snr comments - doesn't sound right to me!

I would have thought you want interleaving ON so that your line runs as clean as possible.

Also are you 'tweaking' at the moment? If you are I would undo that. But you could even try tweaking to get a slower/cleaner line for a couple of weeks to see if that gives things a kick.
What level of errors (FEC/HEC/CRC/ES) are you seeing at the moment?

FWIW - My line is pretty variable but I see TSNRM changes after a few weeks of my line running with low error counts. I also restart my router each morning which doesn't seem to hurt things - so I think the 'constant sync' idea is an old wives tale.

Sorry, sig is a bit out of date there- its been stuck at 15 for months

Tweaking? I have used DMT in the past but havent bothered for quite some while in case that was affecting things. If you mean windows packet settings, all is standard.

Thanks for the heads up, I will try and get James from ADSL24 to look at this.

netgear GT

Download RouterStats Lite (I find the full version difficult for some reason but you could try it if you want). Both can log to file as well as graph, which is useful for sending to people.