If you own a 2011 Mac (iMac, MacBook Air, MacBook Pro or Mac Mini), you most likely have an EFI Firmware Update waiting for you in software update.
This update improves the reliability of booting from the network, addresses an issue that can prevent HDCP authentication after a reboot, and resolves an issue with boot device selection when a USB storage device is hot-plugged.
Software Update Versions/Links:
