Yeah, after I put a second EB Cobalt flat on my bass and it wouldn't intonate either, I was really confused. It had to be something in the bridge or the nut, I thought, but I couldn't see a problem. But it just couldn't be two bad G strings in a row, could it? The odds were about the same as winning the Powerball! But that was exactly what it was. (Unfortunately, I have never won the Powerball.) 