Having an issue with changing my resolution

[DragonNeos]

Have you tried to enable the option "Enable saving GE screen to Textures instead of Memory"? This option should help to increase the resolution of the game's graphics when the screen is maximized. Also, take note that you should not fiddle around with the options in the Display tab of Configuration. If you do, you get the problem like you have described in your post.

To get back to default settings, delete the Settings.Properties file from the folder and then load JPCSP.