[MartinH]

I've found another case where the first pen touch does nothing, and this might be happening to me more often than the 30 second delay I mentioned in the previous post. 

If you do a pinch resize and don't remove your fingers, the next touch will be ignored. This doesn't sound like a problem, but pretty frequently the palm rejection isn't perfect and gets detected as a pinch zoom for a second before rejecting the contact. If this happens when I place my hand on the screen to write, the next pen touch is ignored.