I am making a note of this bug here as Zyxek tech support is not that brilliant and I would be wasting my time.
The latest firmware (from last July) provides IPv6 support and generally works as well as previous firmwares - but it breaks an internet connection if one overrides the router's DNS servers by endering different ones on a given PC. Tested in windows 7 and XP.
DrT
Stress - the condition brought about by having to resist the temptation to beat the living daylights out of someone who richly deserves it.