I emailed Kevin again......
They're not giving too much away however.
His response was (to the effect) that my current PSU should be OK with a different (non Asus) mobo.
I take this to mean that they are accepting I may have an incompatibility, currently, and are prepared to help, just in case.
I don't care too much whether they hold their hand up officially or not: I'm just pleased to be getting some help, without being told to p*** off, because my seven days are up.
In any case, if the article (link) I posted earlier is correct, and I was asked to attribute 'blame' for how the 'incompatibility' occurred, I'd have to say that I think Asus are to blame for implementing a 'feature', apparently without warning/discussing the issue with the PSU manufacturers.
finlay666, the link I posted earlier said that Seasonic had now modified their design.
It could be you were lucky and myself unlucky, in what we got off the shelf.