I'm using an Asus Transformer Book T100 running Windows 8.1, Unity 4.5, NGUI 3.6.6
The problem is with touch handling. For example, when I tap the button, it will stay in press state until I tap couple times on it again. The UIInput field won't get selected until I press it 3-4 times repeatedly fast. Every time I touch the the OnSelect(true) method gets called(by the UICamera) and as soon as I lift my finger, OnSelect(false) is called. So the textfields get selected and deselected the moment I tap. It seems to be a common problem about the way windows pc touches are processed.
I have tried reimporting the unitypackage into a new project. Tried running in editor and in standalone. Disabled Mouse, Keyboard and Gamepad input from UICamera. None of this helped. Do you have a fix for this?