When I set it to "On" it will work. When I set it to "High" it won't work. Also, no matter if it works or not, it will always default to "Off" and I have to turn it back on whenever I start the game.

Have you tried modifying the config.ini file in your vendetta base directory to ensure it starts with the desired settings?

I looked but I couldn't find anything related... maybe I'm just blind

[directx9]
version=3
windowmode=0
vsyncoff=1
gamma=8
triplebuffer=0
mipmapfiltering=2
texturefiltering=2
envmap=1
bumpmap=1
specular=1
illummap=1
textureresolution=-1
texturequality=32
dxtc=0
aa_type=0
aa_quality=0
multipass=0
ps_hack=0
surroundmode=0
automipmap=1
maxmipmaplevels=5
shaders=1
maxshaderversion=65535
normalizenormalmaps=0
fullsize_copybuffer=1

[Vendetta]
version=3
maxframerate=120
sensorsort=4
firsttime=0
cache_resources=0
AudioDriver=Vista Sound driver
VideoDriver=DirectX9 GKGL driver
xres=1920
yres=1080
bpp=32
reset_fov_hud=1
sort_by=4
si_unit=3
flashintensity=100
colorchatinput=0
colorname=1
enableTouchMode=0
showtooltips=1
showlowpowerdialog=1
showlogoffconfirmation=1
showsethomeconfirmation=1
showsellallconfirmation=1
showhelpstring=0
showbarupdatenotification=1
showgroupkillnotification=1
mss=0
HUDradar=1
HUDcrosshair=1
HUDtargetdir=1
HUDleadoff=1
HUDchat=1
HUDdistance=1
HUDspeed=1
HUDenergy=1
HUDdamagedir=1
HUDselfinfo=1
HUDtargetinfo=1
HUDlicense=1
HUDmissiontimers=1
HUDaddons=1
HUDcargo=1
HUDgroupinfo=1
HUDflightassistindicator=1
HUDflightassistnotification=1
HUDautoaimindicator=1
HUDautoaimnotification=1
HUDnfzindicator=1
HUDcentered=0
HUDShowRadarTextLabels=1
show3000mnavpoint=1
usefontscaling=1
fontscale=100

[directx8]
version=3
windowmode=0
vsyncoff=1
gamma=8
triplebuffer=0
mipmapfiltering=2
texturefiltering=2
envmap=1
bumpmap=1
specular=1
illummap=1
textureresolution=0
texturequality=32
dxtc=0
aa=0
multipass=0
ps_hack=0
surroundmode=0
normalizenormalmaps=0

Nevermind, I got it to work. Think it was my folder settings.