My opinion it's not the Pi or the BB it's the Hub. Low quality hubs provide low quality and will not be suitable for every application. The statement above the Pi hates USB the device didn't work until Minepeon? It's still the same Pi different OS? Also backfeeding power from a USB Hub really shouldn't happen that's why it's a powered Hub it doesn't need power from the source nor does it need to feed power back to the source. These hubs are intended to be powered or non powered the issue is you won't connect many devices to a hub that is solely powered from the source and not the Outlet.

The Pi is designed for a 1A power supply = Model B consumes upto 700mA the 2 USB Ports provide 140mA each that's 980mA of the 1A . This design accommodated for Keyboard, Mouse or Wireless low power consumption devices. So cheap devices.

You can safely back feed power to the Pi from the USB and make it the only source of power but a HUB that provides 1A back through that connection would be stealing that power from the other devices. I run an Atrix Lapdock and the Pi get's it's power solely from the Lapdock and have no issues. (It is a quality product better be they wanted $500 new luckily the price dropped to around $40 for a while)

If an ASIC needs 500mA typical 4 port Hubs come with a 5v 2A supply 500x4 = 2A that's a risky setup as you may get spikes and down goes reliability. Or just because it says 2A doesn't mean it really outputs that much it could be +/- 5%

The Pi is tricky because devices are assumed to be plug and play and 100% compatible but every device has different components, different chips, etc. I would imagine the BB has just as many quirks with devices as the Pi unfortunately it really is trial and error.

I use Raspbmc on one Pi it has a 4 port good quality D-Link hub but it can only power 2 slim external drives and a Bluetooth dongle for my Keyboard. Before it runs out of power. My laptop can output 1A most only output 500mA I can run 3 Hard Drives because the extra Amp gets the power from 5v 2A to 5v 3A but that Amp comes from the power supply on the Laptop. The solution is to get a 5v 3A power supply for the HUB and then my problem on the Pi is resolved.

The question I have on the Miners are they say 500mA but do they spike past that ever? Even for less than a second.