I was running DSLstats on the laptop ( wireless ) while checking behind my PC , which was off but plugged in to a socket thats switched off. When I removed the ethernet cable from the back of the PC CRC errors shot up SNR margin dropped , so plugged it back in everything returns to normal . Then as an experiment unplug the PC from the power socket and that shows CRC errors but not as dramatic , could this be an earthing problem ? or my old reliable Billion 7800N cheers