I've just had a reply on the TalkTalk forum, where they have noticed a high level of errored seconds.
My slight concern is that this could be a separate problem.
For the past few weeks I'd been using the TP-Link modem that I got from the cats charity shop, as it's wireless reliability was superior to the TT supplied D-Link one.
However, the TP-Link modem ran incredibly hot (I ended up taking it out of it's case) and seemed prone to disconnecting and resynching at a slower speed in the evening.
I decided that the modem must therefore be a bit on the faulty side, and so went back to the TT D-Link modem.
Which, over the weekend, started doing the same thing - losing it's 21K conneciton and resynching around 18K.
This morning I noticed a high number of error seconds, 3300 ish, when the modem had been running for less than 20 hours.
The line has up to now proved very reliable, I think I've had maybe 2 or 3 resynchs in the 15 months I've been with TT. Error seconds aren't usually that high - previously it's taken 166 hours to reach 3000 error seconds.
A wander around with an AM radio found a huge amount of noise coming from the PSU for that bargain NAS disk I bought from eBay.
Yesterday I moved it away from the modem (it was plugged directly into one of it's LAN ports) but I still had disconnects in the evening, with lower speed resynchs. This morning I've unplugged it entirely to see if it resolves the problem.
Curiously, though, the pages partially loading problem had gone away all day yesterday, even though I was still getting high error seconds and disconnects.
This is why I wonder if there are two separate problems here.
Lets see..
Ian