I've heard of this problem before on the forums, but I thought it had been fixed. At some point I anticipate Jason will post and give you an accurate status on what, if anything, can be done about it.
The 'n' key was the problem in the previous posts. I never use the 'n' key. When I want to see which units still have action points, I put the screen in one of the 3d modes and hit the 't' key, which brings up a thermometer for each unit. If the thermometer is full red, then the unit hasn't used any action points. If the thermometer isn't red but is blue or green, then press 'u,' which will bring up a unit screen on the right. Click on a unit, and then click on the red part of the circle for the unit. That'll put the thermometer on the action points.