I've recently bought one of these: http://www.westerndigital.com/en/products/products.asp?driveid=372 I've ended up using it as my primary hard drive because my internal one has pretty much died. I leave my machine (Core Duo 20" iMac) online overnight to download stuff (I set the monitor to switch off after a minute) and the problem I'm having is that when I get up in the morning the hard drive has frozen. The main light across the middle stays lit constantly and the only way I can get MacOS back is to forceably power the Mac down, unplug the hard drive from the mains and Mac and then plug it all back in and switch on. As you can imagine, this is really irritating and I'm wondering if anyone knows of a possible solution? I have tried telling it not to switch the hard drive off (in the power settings) but the problem still occurs.