A few days ago, my nephew happened to find and push the power switch on my surge protector attached to this computer. Since then, the phasing on my monitor goes bad after one of two instances:
1. I reset the computer
2. I enter and then exit (or Alt-Tab) a fullscreen application.
Alongside bad phasing, whenever I reset the computer, the desktop is shifted slightly off the screen, which can be fixed with auto-processing. The only thing I can do to fix the phasing is to power off my monitor and re-plug it in.