For me, my computer boots fine with no USB devices attached. If I plug in my monitor's USB cable before boot (a Dell U2711, which contains an integrated SD card reader), I receive the "illegal sector size" message. The correct boot device is a SATA SSD disk; it certainly seems like plugging in the SD card reader messes up the device numbering.
I'm using an ASUS P8Z68-V motherboard with a UEFI bios, running an up to date version of Ubuntu Precise.
For me, my computer boots fine with no USB devices attached. If I plug in my monitor's USB cable before boot (a Dell U2711, which contains an integrated SD card reader), I receive the "illegal sector size" message. The correct boot device is a SATA SSD disk; it certainly seems like plugging in the SD card reader messes up the device numbering.
I'm using an ASUS P8Z68-V motherboard with a UEFI bios, running an up to date version of Ubuntu Precise.