Just wanted to mention that I too have had problems updating the firmware on both Linux and Windows. At some point in time I succeeded using Linux once, but wasn’t able to reproduce it later. Couldn’t remember which Linux and which specific steps. In all cases detect device never found the device.
However using a MacBook Pro (OsX 10.9.4) it worked flawlessly. Both the detect hardware and the upload firmware (after entering the boot-loader a 2nd time) worked without a hitch. I don’t own a MacBook and was lucky I had access to one. It’s not a solution of course, but it could help someone get past this problem temporarily.
I haven’t tried the command line yet so I will try that the next time I need to update.