I have had my new white MacBook for about 1 week. After about 2 days, a small yellow discoloration popped up on the mouse button and where my hand rests when I am using the trackpad. Yes, I wash my hands many times throughout the day......I am a dentist. I did eat a couple of Wheat Thin crackers while using the computer a few days ago. Could the oils in the crackers cause this? Could be from the latex gloves I wear. I have tried every method I can think of to remove the stain to no avail. I hate for my beautiful new Apple to look dirty so fast. Any ideas? Thanks!