I've had DSL for 3 years or so, for as long as I remember I've always had CRC error's but on services 2mbit and below they didn't effect the speed of my service or cause disconnects. However on Max they're causing me headaches, the SNR margin is above the 6dB limit BT set for Max services all the time however, CRC error's appear to roll in which I cannot understand. Why is the data getting corrupted if there is sufficiant signal to noise ratio? I can sync at 8mbit and there's margin to spare so I know the line would be able to take it if it wasn't for the CRC Error's. I sometimes receive several hundred in just a few seconds causing the router to drop the connection and resync with the exchange (sometimes at a higher(?) speed). My lines current sat at 5mbit with 15dB SNR and this moment in time I'm getting 2 CRC Errors per minute. What's causing the CRC Error's and if it's noise, why isnt it being reflected in the SNR?