My modem is a Draytek Vigor 130 and I'm on 2 Degrees.
My first point of call was my wiring. I have no landlines so i disconnected all but one phone jack And my speed did increase a bit, but my error rate didn't go down. DLM chopped me back a bit but it's now taken me back up to 30mbps with lots of errors.
Next I tried adjusting my SNR margin delta. This didn't make much difference to my error rate.

Here is a screenshot of my modem stats. Basically, are these error rates too high? And if so, should I contact my ISP to get it sorted?