As for guidance not being upgraded, I'm not reading anything...

As for guidance not being upgraded, I'm not reading anything into that either.
I believe it would be naive to believe 2nd half to be flat?
Perhaps they can't accurately forecast how much they will exceed guidance by at this stage and rather than state a random figure, are waiting on the results of some large contracts. Nothing worse than companies fluffing around with guidance. I will admit I do like companies under promising and over delivering.

I reckon, dare I say it, a profit upgrade will be released before Easter..... watch me get quoted on this haha.

Some numbers
1 2015 - 37.8
1 2016 - 55.8 (+48% on previous year)
1 2017 - 70.6 (+26% on previous year)

2 2015 - 41.1
2 2016 - 71.3 (+73% on previous year)
2 2017 - 75.6 (+6% on previous year) <~~~~~~~~~~~~~~I don't think so.