Okay then.. I'll list all the settings I have tried since this problem started:
IN NON WINDOW MODE:
RESOLUTION:
640 x 480
800 x 600
1024 x 768
1280 x 1024
SPECULAR:
YES and NO for all resolutions listed above
SHADOWS:
YES and NO for all resolutions listed above
DECALS:
YES and NO for all resolutions listed above
PARTICLES:
HIGH, LOW, and OFF for all resolutions listed above
TEXTURE QUALITY:
HIGH, MEDIUM, and LOW for all resolutions listed above
FRAMERATE:
30 FPS, VSYNC, and NO VSYNC for all resolutions listed above
IN WINDOW MODE:
RESOLUTION:
640 x 480
800 x 600
960 x 600
1024 x 768
SPECULAR:
YES and NO for all resolutions listed above
SHADOWS:
YES and NO for all resolutions listed above
DECALS:
YES and NO for all resolutions listed above
PARTICLES:
HIGH, LOW, and OFF for all resolutions listed above
TEXTURE QUALITY:
HIGH, MEDIUM, and LOW for all resolutions listed above
FRAMERATE:
30 FPS, VSYNC, and NO VSYNC for all resolutions listed above
The settings I usually play with are 800 x 600 in window mode with the three yes and no ones set to no and the particles and texture quality set to low and framerate on vsync.