I have a dual boot using grub. The system has sda for XP, sdb for Linux (sdb4 common Fat32 partition). Both drives are internal SATA. I also have a (usb) scsi external drive. If it is 'on' when grub loads, I get error 17. I also get an error 17 if a usb memory stick is connected. If no usb external drives are connect/on, grub works normally. Any ideas? Mike