Taiwan. There wasn't much in the way of creaking before today. My guess is that it broke open while I was standing on the cranks, going up some hills. It's sad though, and I agree that it's likely due to a flaw in the brazing. I could be wrong, but I just can't see that much water getting in the seat tube. I've got fenders on it, and usually the only time it's out in the rain is when my butt is in the saddle.