Hey guys, first post figured I'd contribute.
Just bought a FX1000 and I am an android user.
Had all the same issues (failed firmware updates) following all of L6's instructions.
Tried 3 different PC's, 2 different USB cables, several USB ports. All attempts to update firmware failed.
Tried a friend's Mac OS laptop, firmware update worked fine and was SUCCESSFUL.
If anyone is having trouble with failed updates, it seems the easiest way is to just find a friend with a Mac and download the updater and try it on that. Not an ideal solution, but it was plug-and-play easy, no drivers just the updater.