Emulator keeps switching back to windowed mode

[User Name For This Forum]

I'm having a lot of trouble with this emulator. I was playing Shadow of the Empire fine yesterday, switching from windowed to fullscreen at will when the resolution was at 640x480 because I cannot play at my PCs native resolution since the emulator inexplicably upscales everything along with the resolution. But now ALL OF A SUDDEN I can't switch to fullscreen with Alt+Enter anymore, it switches back to windowed unless the resolution is maximized which makes the game extremely slow. ALL OF SUDDEN! I didn't change a single configuration! If this continues I might as well delete all semblance of this thing from my PC and switch to Retroarch.