I just upgrade to version 1.21.0.0380. Sometimes when I left click on a slide only one of the "selectors" moves to that slide. I have to double left click often times to get both selectors to move. It tends to happen regularly after I add a slide from the Add Item list. It is also a problem if focus is in another window (like Chrome) and then I try to click on a slide in Proclaim. I discovered this problem when seemingly random slides would be removed when I pressed Delete on the keyboard.
It looks something like this with the yellow selector on one slide and the black gradient selector on another:
