I think my wireless mighty mouse's scroll wheel is defective (can't scroll up), it scroll's down. I purchased it along with my 24 inch iMac last December. Is it under a 1 year warranty or 90 day warranty. I am having a hard time googling the answer on apple's website. Also, I have a 3 year Apple warranty on the iMac. Does the warranty apply to the wireless mouse/keyboard since I purchased it in the same package?