I can only seem to get either my U3 or new R-box running at a time, and have Zadig'ed many a time. Is there no way to get these running together? I've tried multiple USB hubs, powered and unpowered.
In your own words
Engineering > all.
The designers of both of these devices gave them identical (crap cheap) usb communication chips and have set no identity for manufacturer or product so now about a dozen different devices look identical on the bus. The best cgminer can do is poke it with a stick a few times till it goes ouch in different ways to say "hmm, looks like a frog" and then gives it the rockminer driver. This reliability of this is variable and works in my testing on linux. Perhaps it might work better if you start cgminer with one connected and plug the other one in after since hotplug works slightly differently. Sometimes they dont like to let go of the same USB bus ID so need cold power cycling. I can no longer do any more testing since bitmain sent me 2 U3s and it appears I've fried both of them (hence my warnings earlier on).