Why are textboxes being given focus when I click on buttons that are above it?

Question

I've got an mxml view, with a button in the actionContent and a viewMenu with two buttons.

In the main content I have a scroller and a vgroup, within which are a few textboxes, labels and buttons.

If I click on any of these 3 buttons when a textbox (TextInput or TextArea) is below them I end up focussing on the textbox rather than firing the click even of the button.

Does anyone know why this is happening? Is this a common thing, because I couldn't find anything about it searching google or here.

Btw, testing has been done with a physical iPad (1 and 2) and iPhone 4, as well as the emulated iPhone 4S and HTC Wildfire.