Take a stero file. Select to view both channels separately in the wave viewer. Adjust channels to mono. The buttons are now grayed out but you can't switch to a new view, and the current view is inaccurate, as you will see if you switch back to stereo and try playing it. Surely it should force a switch back to the combined view if mono is selected?
I would also have assumed that converting to mono would have *mixed* the two channels, not (as it did) taking the left one and discarding the right one.