Last version I can recall the layer mask icon updating correctly was the current retail 1.6. It still will not update when you invert or paint on it. I guess it's not that big of a deal, but everytime I invert a layer mask, I look at it to see if it did invert. When it remains white you don't know until trying to paint on it. Please fix this before 1.7 is released for retail.
Tried this with a straight layer mask and it works correctly with it. However it does not work correctly with the Filter and Adjustment layer masks.