This has happened 2-3 times over a month or so.
Sometimes when I start my computer and hover over the items on the right side (i.e. libraries, Homegroup, Games, This PC, etc.), the preview icons that are supposed to display on the top right corner appear blank. My Windows log-on photo fades out and is replaced by nothing when I'm hovering. If I move back into the left side, my photo reappears. Playing around with Start8 settings does not change anything. It seems the only way to fix it is to restart my computer.
Comparison of the bad vs. the good:

