Just a guess... your desktop resolution and color depth must be different from the resolution and color depth settings in the OpenGL plugin right?
If that's the case, try this. Change your desktop settings to match the OpenGL settings. Then bump up the refresh rate. Apply the settings. Then revert back to your regular desktop settings. Then run ePSXe. I have a GeForce2MX, and this is what I have to do everytime I install a new driver.
If that's the case, try this. Change your desktop settings to match the OpenGL settings. Then bump up the refresh rate. Apply the settings. Then revert back to your regular desktop settings. Then run ePSXe. I have a GeForce2MX, and this is what I have to do everytime I install a new driver.