Could it be the cover plate on the back of the discs? I had to prize mine out a bit with a screwdriver because the left side was scrapping on the disc when turning.
Unfortunately I hit the car coming out of my drive, a concrete/stone wall has gone down the passenger side , so the car's at home and I have my mum's Stilo at uni. Once it's all fixed i'll sort this out and dig the thread back up