I've just fitted a Grohe (38 690) WC which has a dual flush. The button
bezel contains 2 buttons formed into a circle: a small elliptical button
and a larger button in which the smaller sits.

See http://www.thejohnsons.co.uk/GroheButtons.jpg > for a 17KB

The mechanism was pre-assembled by the company which supplied bathroom
furniture, but I have checked that the air hoses are connected correctly
(it doesn't work at all when switched) and the assembly looks pretty
much the same as the enclosed 'instructions'.

Now, on this Grohe mechanism, if I press the large button, it depresses
on its own and gives a large flush. If I press the small button, it
carries with it the larger button and then gives me a small flush.

This concept just seems wrong to me: press 1 button for a large flush;
press 2 together for a small one. Surely it's the other way around: 1
for a small flush; 2 for a big?

Anyone else got a Grohe flush -- or similar -- with whom I can compare