I have recently switched to using a mac after buying an iMac with the following specs - Processor Name: Intel Core 2 Duo Processor Speed: 3.33 GHz Number Of Processors: 1 Total Number Of Cores: 2 L2 Cache: 6 MB Memory: 4 GB Bus Speed: 1.33 GHz Boot ROM Version: IM101.00CC.B00 SMC Version (system): 1.52f9 System Version: Mac OS X 10.6.4 (10F569) Kernel Version: Darwin 10.4.0 I then bought a 500 Gb Buffalo Dualie (one of these http://www.dualie.net/) to use as an external HDD. The HDD is connected through USB, and I'm using it with Time Machine as my main backup drive. It worked for a few weeks at the start, then refused to mount. I tried a number of things such as repairing it using Disk Utility, reformatting it, trying to mount using Disk Utility, using terminal commands to try to force it to mount and none worked. Eventually I gave up and assumed it was a dud hard drive and returned it to Apple who gave me a replacement. The replacement worked fine for a couple of weeks, and now the same problem has started to occur. The hard drive has a built in iPhone dock which continued to work for a while after the hard drive itself wasn't being recognised, but it's stopped recognising the iPhone at all now. I'm not sure where to go next, as returning the hard drive again would likely result in the same problem, so any help would be much appreciated. Thanks!