Hi When I turn on my Macbook it all fires up OK, then an error box opens with this message.. A volume failed to mount. The volume "MacHD" could not be mounted. In the error box is a picture of a drive with three little people upon it. I cannot find this volume anywhere, but if I boot the Macbook with Airport turned of it does not happen. I assume this volume is something to do with the main machine, I used to have a drive called this but it no longer exists. How can I stop this happening ?