Keyboard adjustment keys have black box around them

I recently did a fresh reformat and install of Yosemite on my macbook pro, it was working as expected until today when i noticed that whenever i use the top keyboard row keys to change something like screen brightness, volume, backlight level, there is a black box around the rounded box that normally pops up. Is this a common problem with yosemite and is there a fix?

This effect occurs when "Reduce Transparency" is enabled (System Preferences > Accessibility).

(Very odd that this is how the effect would degrade, instead of just make it a solid colored square.)

I solved it accidentally on my 2009 macbook pro running 10.10.3 by removing the battery, unplugging the charge cable, and holding the power button down for 15 seconds. I was trying to reset the SMC/PRAM for unrelated reasons and noticed the black boarders are gone.