1.0 driver slow replacing texfetch by tex2D


I’ve just installed the 1.0 SDK and toolkit. I’ve developped an application on a GTS8800 under Windows XP using textures (with texfetch). I’ve changed with tex2D as it is done in simpletexture example and now my execution time is the double (100 ms vs 50 ms before). This is a really a huge difference!
Is there a trouble with the 1.0 driver???

sincerely yours