Yes. I did a V-I curve of the wall wart and it was fine. I inspected the ripple under load with my scope too. I also had it hooked to a TTI bench PSU at 5.000v and it still had problems (I have a large selection of proper test gear at my disposal).

They didn't like those facts.

Then you've got a dud. Lots of the first rev in particular had a few problems like this. That's ample evidence to exchange it for a new one.

The later revs, particularly the B+, seem much more reliable (although occasional duds definitely do still happen).

Well you're probably right but after that face full, it went in the bin as i don't have the inclination to see if my time will be wasted again.