Hi, I have a Intel 2.2GHz Macbook running Leopard. i just bought a 500Gb 7200rpm drive for it and stuck it in a sata->usb enclosure for the time being till i've got time to install it. i figured i might as well install Leopard on it in the meantime, which went fine. after installing the os, it booted nicely from the USB drive and i proceeded to download the combo update and installed that. subsequently, i rebooted to the system drive to use some programs, and now i want to reboot back into the installation on the usb drive, it's ignoring it and booting from the system drive. things i've tried so far: - setting the USB partition as default boot partition under System Preferences>Startup Disk - unchecked "Ignore Ownership" for that partition in Finder>File>Get Info - chmod 775 - repair permissions in disk utility none have solved the problem. the partition used to show up when holding down the Option key on boot but it doesn't anymore for some reason. any ideas?