Ive got a bitshopper version of the stick and I occasionally have the same problem. I have to hotplug it sometimes upto 10 times and restart cgminer before its recognised. But once it is will happily run 250m.
Strangely enough ive found its most tempermental when its cold. Once its warmed slightly, even if you hold it in your hands, it starts up the first time the majority of the time.
Interesting. I'll try leaving it in my garage for awhile, it usually warms up in there compared to the rest of the house. See if a "warm start" can get things going again.
General question, if the light is green, and it pops in cgminer enough to get the serial and start cycling (reset, zombie, no hash, reset, zombie, no hash, etc), is that generally a sign there is hope it's not dead? Is there any other way to probe it or check to see if there is any hope?