I read some of the archived posts about noisy KDWs and the theory that "slipped belts" are common with these tires. One of mine is making a ton of noise (I rotated it to the back, and the noise followed it, so I know it's not a suspension or alignment issue). My question is: How safe is it to drive on a tire with this issue? BTW, the tires all have about 30K mi. on them, but still have a surprising amount of tread left (no driver's schools or Auto-X's for me in since I've had the tires).