Final Fantasy IX combat problem in epsxe

Lately, I've been trying to run Final Fantasy IX on epsxe. After some configuring, I got it to work for a while, but now battles are not working properly.
Everything runs smoothly, but when a battle occurs, every sound plays twice, and the video slows down and lags.
I'm using Pete's OpenGL2 for my video plug-in with the following settings:
Plugin: Pete's OpenGL2 Driver 2.9
Author: Pete Bernert
Card vendor: ATI Technologies Inc.
GFX card: ATI Radeon HD 5700 Series

Resolution/Color:
- 832x624 Window mode
- Internal X resolution: 2
- Internal Y resolution: 3
- Keep psx aspect ratio: off
- No render-to-texture: ?
?

- Filtering: 6
- Hi-Res textures: 1
- TexWin pixel shader: off
- VRam size: 0 MBytes

Framerate:
- FPS limitation: on
- Frame skipping: off
- FPS limit: 120.0

Compatibility:
- Offscreen drawing: 1
- Framebuffer effects: 2
- Framebuffer uploads: 1

Misc:
- Scanlines: off
- Mdec filter: on
- Screen filtering: off
- Shader effects: 0/1
- Flicker-fix border size: 0
- GF4/XP crash fix: off
- Game fixes: on [00000002]

I'm using the sound plug-in that was provided with epsxe. I've tried other sound plug-ins, but they don't work properly with the emulator.

The game is running off of an official disk.

Thanks in advance for any help you can provide.

It might be your Sound Plugin.

I have a similar issue. In the end, I changed into Pete's D3D Plugin and it works fine. It's too bad since I prefer Pete's OpenGL plugin. Maybe my GPU is not powerful enough.