hey forgive me for sounding dumb, but does anyone know why my front hayes disc brakes are making a scraping sound when pressed moderate to hard? I have just bought a new giant trance3 two days ago and the brakes sounded fine for the first day, then yesterday the front brakes started making this scraping sound. I took it in to the bike store today, the guy said that a part of the pads had gone hard and shiny so he sanded it down.... brakes were fine for a couple of laps around the block then when i get it home and go for a long ride the noise comes back. At first i thought it was normal, and i dont know maybe this is normal and i am being paranoid, but i'm not too happy because i spent a **** load on this bike (for my standards anyway). It may even still be breaking in, but the noise shows no sign of disappearing. I know nothing about bikes mechanically - all i know is that i've been riding bikes not long after learning to walk and i love mountain bikes and riding in general. Help me out, thanks!