FPS stuck at 50 in Diablo 3

I am not sure what was happening, but every time I would join a new game, hit CTRL + R (gives you ingame FPS) it would be locked at 50FPS, even with the limiter at 61, or even off. To fix it, I had to do the following :

For reference, I have an i5 2500k, 680GTX, 16GB DDR3, 256GB SSD.

Go to \Diablo III\D3Prefs.txt

Change setting LimitForegroundFPS from 1 to 0
LimitForegroundFPS “0”

I also reset LimitBackgroundFPS from 1 to 0
LimitBackgroundFPS “0”

This fixed it for me!