Thanks for the reply yes it's BTC and I was thinking the same about the HUB so hopefully I am going down the correct path. Is the Error column strictly Hardware Errors then?
USB Hubs are usually the cause of issues, the Pi is quite sensitive to them and bitcoin mining often exacerbates any problems, it is quite intensive on the bus and timing is critical.
Often a good v1.1 or 2 hub with a grunty power supply is your best bet and USB3 is somewhat of a no go area.
Neil