I bought some time ago, block erupter usb miner. Finally, when I got it to authenticate and multiminer work so it gives me a 100% error.
Are you using a powered USB HUB? All USB ASICs require enough power or they will not work. I'd try a powered USB hub. If that doesn't work it sounds like potentially a bad ASIC.
I use computers usb port. I think it should be good bitminter can use it guit well for alrmost 24 hours strait. I got it almost work in bfgminer only gave like 90% rejected shares.