My mono hudson had this problem on one of the roller bars on the buckle where the tongue lies on. It actually turned the leather lying beneath it black from tarnish. I took it to my local boutique and they tried at first to tell me that this was normal and that the hardware after time may tarnish. They said that their display bags have tarnish on them. I would not buy this, esp. since the other buckles had no problem whatsoever. The metal tongue on that one paticular buckle was rough underneath, like it wasn't polished smoothly, so common sense tells me that that was the culprit for causing the rollerbar to scratch and tarnish. Therefore, I insisted that they send it it in for repair. They emailed LV and sent a picture, and called me back to say that they would go ahead and replace the entire buckle. Man, I feel like sometimes you really have to be persistent and even on the edge of a jerk before they'll do anything.