thx ck.
After cgminier restart the same unit that was showing that error now shows zero value for A: R: and /m but correct hashing speed. Is it safe to assume the unit is actually not doing anything?
Anyone seen below error before and perhaps knows what it relates to? I'm suspecting it's some kind of limitation on USB hubs (1a40:0101 Terminus Technology Inc.).
USB: AMU0 read1 buffering 252 extra bytes
It means cgminer found a lot more information from the device than it was expecting, but it's harmless and the equivalent to a hardware error.