Hi there,
Please do post the stats as Jim has mentioned, but it does look like you've had a few disconnections:
<img src="http://community.plus.net/visualradius/generated/image13910782947608.png"/>
That'll be what's caused the line speed profile to change, though it's back up to around 2600 at the moment (and matched on our side) so not looking as bad as it was. If it remains stable that should improve further, though we'll know more once you've posted the line stats from your router as per Jim's link.
