Hello,
I've just downloaded AW2 on my iPad 4 and started the single player campaign. Part way through the 1st mission on the tutorial the dialogue boxes stopped appearing. I could still see the character art pop-up which indicated there should also be a dialogue box at that point.
I had restarted a checkpoint part way through after which the dialogue boxes disappeared but I can't remember if any showed up after this action to determine whether the two were connected. I'm using an iPad 4 which is on software 6.1.3.
Thanks,
LMT