I bought a Western Digital My Passport Essential SE 750 GB USB 3.0 and USB 2.0 Ultra Portable External Hard Drive WDBACX7500ABK-NESN in 2010 on Amazon and have used it first for my 2009 MacBook Pro and now for my 2012 MBA. The problem described below didn't occur with the MBP.
No matter if I plug it in the right or left USB port on my 2012 Air, if I move it just slightly while connected, it disconnects even though it still by all appearances, is plugged in to the USB port. As stated above, I didn't experience this problem when using it on my previous 2009 MacBook Pro.
No matter if I plug it in the right or left USB port on my 2012 Air, if I move it just slightly while connected, it disconnects even though it still by all appearances, is plugged in to the USB port. As stated above, I didn't experience this problem when using it on my previous 2009 MacBook Pro.