I wouldn't worry about the joint itself. It looks better than many new rims I've had and the bump felt in the brakes went away quickly on their own as the pads wore them in.
Did you perhaps hit a big bump recently? Maybe re-adjust the pad postion? Check and make sure there aren't some really loose spokes that might be letting the rim joint begin to move too much.
However on a rim that is from 2001, then you might have nearly worn out the braking surface. A shop with a good wheel person can tell you more about it.