I was getting so annoyed with the shoulder buttons, that I decided to open the pandora and have a look.
The problem is that the hole for the hinge is too big, and off center.
So instead of the button rotating around the hinge like it should, it just wobbles about a bit.
This makes them very hard to press, and almost impossible to use at the same time as the other controls.
These should really be replaced by proper fitting shoulder buttons.
Another problem was that one of the screws was overtightened, and had snapped off part of the plastic that it goes into, which you can also see on that picture (top left).
It just kept on twisting when I tried to get it out.
It didn't cause any problems though, and the other screws manage to keep the case closed quite nicely. (which is probably why it went undetected)
But please be more careful here when assembling the other pandoras