I think we can do something to help to determine if this is a matter of hardware differences issue. We need to find the serial numbers of the units which are unable to get v1.4 installed and also the ones on which have worked flawlessly, so we could find a range of serial numbers with problems. That will be a very useful information for Yamaha to find out what is happening (I hope someone here has a direct way to get that info to them, once it is compiled)
I have no problem on sharing my unit serial, which is Genos E Ser No. EEY101285 on which I installed v1.4 without problem at first attempt.
Please, note that there could be localized versions for the Genos (as mine is Genos E, I guess from 'Europe'). But I am sure we can find a pattern if there are enough contributions.
Jose