[downquark1]

Well this is why I don't like ADSL, its far to sensitive to problems. Basically the noise margin will change during the day, I find it weakest around this time. On a sky router if it drops below 6 you will get connection problems.

Remember as noise margin goes up sync speed goes down. (speed V stability)

Now the router decides what margin to set at, when you turn it on it will go for the highest sync speed it can get with a noise margin at 7. Or if it can reach the speed cap without going below 7 it will hold at the cap and get the highest noise margin it can. Now as the noise margin goes down in the evening it should ideally readjust so the sync speed drops to keep the noise margin stable, but this doesn't happen (or not yet at least). So you can either turn the router on in the evening when the noise is at its worst, so it finds a comfortable margin which will go up during the rest of the day. Or you can force it to have a larger margin.

These are assumptions derived from experience so please correct any mistakes.