I've seen similar situations. EG when I tried to set 512*384 (listed as supported) it gave me some kind of dos gfx garbage screen.
I suggest to offer only common resolutions, autodetect screen ratio (4:3 or 16:9) and additionally offer a screen settings dialog that can be started in windowed mode alternatively.
Not sure if it's possible to write a function that is capable of detecting if a resolution is actually working. You could use the webcam dll, then monitor the screen - just kiddin.
I suggest to offer only common resolutions, autodetect screen ratio (4:3 or 16:9) and additionally offer a screen settings dialog that can be started in windowed mode alternatively.
Not sure if it's possible to write a function that is capable of detecting if a resolution is actually working. You could use the webcam dll, then monitor the screen - just kiddin.