My sister borrowed my old Canon Digital Rebel XTi camera. She saw some dust while she was taking some photos, so she figure she'd clean it. She didn't cut her nails yet and tried to get to some tough areas inside the camera, and scratched one of the two mirrors(?) inside. It's the one where it has the focus points printed on it; the one on top. I saw it somewhat has two layers (I think), so I was wondering if I could just replace the layer that was scratched and install a new one? Is that possible, or do I have to buy a new camera? If so, where can I get it replaced/fixed? Can I ask Canon to fix this even though my warranty has expired? (I'll pay them, of course.) Please help me! Thanks!