Just to clear it up, a dx9 card will work if you have any other version of dx installed, it doesnt have to be 9. GP3 has got some isssues with dx9, but its usually alright, daniel's suggestion seems quite possible - maybe with all that AA and AF gp3 thinks that the card is weak (cos gp3 doesnt work fast with aa or af) so suggests software.
Switch off AA and AF - it doesnt make much difference in GP3 anyway
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She says brief things, her love’s a pony
My love’s subliminal