ah a different problem to what I had, I couldn't get the bolt to turn, but your sump plug keeps turning... is that right?
also I found the bolt was an inbetween size, couldn't find a socket that fitted tightly, and by the look of it others had the same problem. but I might put a crush washer(non flat washer to prevent overtightening) on it again as they are only about $2.50 from nissan.