The router is syncing OK, it's just that your ISP is not supplying the data as fast as your router can receive. That could be exchange congestion (BT) or your ISP's fault.
How long had the router been up when you got those stats? A few minutes and the errors are high, a few days and they may not be significant.
The router had been up for just over a day when I posted those stats. My ISP (Zen) insist they can't see any problem with the line stats, they've checked with BT and say contention isn't the problem either. They've been pretty good anytime I've had a problem previously so I'm inclined to believe them!
The strange thing was that when my speed dropped from around 5Mb to less than 1Mb on Sunday, the connection didn't drop, the router didn't resync (it had been up for 42 days at that point). I was playing a game online at the time and noticed the change immediately. I checked the router, saw the connection hadn't dropped and was still showing 7000kbps, but when I ran the BT speedtest it was only 816 Kbps.
When I phoned Zen's tech support the following afternoon, as soon as they checked the line stats there was a slight improvement although they insisted they didn't do anything. The result of the BT speedtest was then 3061 Kbps (a test download is only showing about half that speed), and that's how it's remained since.
I'm trying to borrow another router to try, and am hoping that will show a difference. If it doesn't. the only other thing I can try is changing the microfilters (though they reckon if that had been the problem it would have shown something in the stats).