I don't think it happens because of cord tension, although I can't rule it out. The cord doesn't seems to be under strain at all when it happens usually though. I get no error messages popping up. It could be the driver I suppose, I'll try reinstalling. It happened 3-4 times daily in one of my USB ports which is slightly looser, and has only happened once in the last 4 days while in the other. I have two 3.0 ports, I'm trying the 2.0 one now.