Button not highlighting when inputmodule executes a pointerEnterHandler even on it.

So I'm using my custom input module code for world space cursors on uGUI with oculus rift, as documented here:

http://ralphbarbagallo.com/2014/08/...ursors-for-world-space-canvases-in-unity-4-6/

But for some reason, some buttons will not highlight when I execute pointerEnterHandler on it (in the SetTargetObject method). It's weird though because I can click them and that animation works, but it's the highlight state that never animates. Each button is identically configured so I can't figure out why. Is there some way to debug event execution so I can see why pointerenterhandler isn't being called on some of my buttons?