Is there any chance that I could install Snow Leopard onto an External HD using a 400 firewire port on a 2006 duo intel iMac? I have been trying this with differing results. The latest install took a very long time and compulsory restart opened up to the main drive. Subsequently any attempt to StartUp on the HD by holding the "T" key down, just gives me an unrelenting Firewire symbol moving around the screen. So I assume the slow install didn't work and Firewire 400 is not fast enough. The external is a 1T Western Digital My Book Studio which has ability to accept 400 or 800 but my late 2006 iMac5,1 has 2, 400 Firewire ports. Can anyone help here? I'll take on board any advice. Regards, Retirado.