I'm waiting for someone from Singapore to write in agreeing:
"it's normal, to be expected, teething troubles, was a big job you know".
"every time we open a new terminal we have the same mess" ...
Or rather I'm not waiting because it won't happen.
This is a very British cockup in the British way of doing things.
BAA & BA probably thought it was "good enough", and they'd get away with it.