Gradual sync rate reduction

[#1]

Hi Plusnet,
As the subject hints at I appear to be suffering a decreasing sync rate as the graphs here illustrate. Note also that the SNR margin variations correlate (cause or effect?).
When looking at my figures over 7 months you can see that the time between resyncs no longer makes it above 10 days whereas I used to have periods of over 20 days at >8Mbps DS sync rate without any interruption.
I can confirm that there have been no known changes within my house/equipment that I can attribute this to.
Could I get you to take a look?
Many thanks,
Mathew

[#2]

Hi there,
The diagnostic checks that I've just run don't show me anything obvious, however it's interesting to see that around week 27 on your graphs there's an increase in power on the upstream which prior to an increase in SNR and a decrease in synch rate on week 28.
I'm wondering if something began to happen around week 27/28 that might be causing increased noise on the line.
Adam

[#3]

That's what I was thinking too. Any thoughts how to work out what? I guess by its very nature it's a difficult one...
I wonder if the hot spell had started then? Perhaps it was slightly later thinking about it...