It's hard to see form the picture on ebay, but the output on that adapter looks like 5v DC 3A. Is that correct? If so, that's too low. The USB spec requires 500mA (.5A) per port. 10 ports = 5A min output from your adapter.
Are the power supplies you are using full ATX or just 12v? If ATX, try tapping off the 5V rails to power your hubs instead of using the adapter.
If you are experiencing a lot of HEs across all of your GSs, remove the hub, plug one of them into your RPI directly, and mine with it for a day. If your HEs go down significantly, then you have found your problem.
Ok good point, i looked into the spec, i came across this
220.127.116.11 Power Budgeting USB bus power is a limited resource. During device enumeration, a host evaluates a device’s power requirements. If the power requirements of a particular configuration exceed the power available to the device, Host Software shall not select that configuration. USB devices shall limit the power they consume from VBUS to one unit load or less until configured. Suspended devices, whether configured or not, shall limit their bus power consumption as defined in Chapter 7. Depending on the power capabilities of the port to which the device is attached, a USB device may be able to draw up to five unit loads from VBUS after configuration. (http://sdphca.ucsd.edu/Lab_Equip_Manuals/usb_20.pdf
So i have the 12 power supply that comes with the GS. I will put the usb hubs on the separate 5V power supply.
As for the hard ware errors i tried both options and they produce the same errors. I guess i would have to move to a different miner software to view the individual errors.