Bumping this in the hope someone sees this, I am having the same issue. I have been playing PoE on my laptop hooked up to a monitor with 1920x1200 resolution. No problem. But right now I am traveling so I brought the laptop sans monitor, and it's running at its native 1366x768 resolution. Every time I try to launch PoE I get the same "Couldn't switch to requested monitor resolution" error with this:
"Switching to resolution 3x0 failed, trying lower one
Switching to resolution 3x0 failed, trying lower one
All resolution switches have failed
Screen: could not switch resolution (1920x1200 fs=1 hz=0)"
UPDATE: I fixed my problem, I believe it was caused by a Windows update (big surprise...). I had to go into my Nvidia control panel-->Graphics Options-->Panel Fit--> and switch from "Maintain Display Scaling" to "Maintain Aspect Ratio." So I'd recommend looking for similar options in your graphics control panel.