Yep, i had to return mine after about 4 months cause there was some problem with the hinge, I could only get sound (earphones and internal speaker) when the C760 had the screen closed or flipped and folded over the keyboard - opening the screen caused sound to stop.
Took it into BicCamera (I have a 3 year extended warranty withthrough them ) and they sent it off to Sharp in Tokyo. Took 2 weeks to get it back and the paperwork that came with it said they had replaced the \"unit\". No probs since then.
Stu