Counter strike source shader problems

[KSI_Gex]

i had been having the video troubles caused by the latest nvidia drivers. i downgraed my drivers to version 71.89 and now my counter strike source says "unable to init shader systemn" when i try to load it. plzplzplz help.
and i have the dx 9.0c update

 

[Ghost (CG)]

i'm getting the same thing and i'm going insane, only just got my pc and installed CS and now i cant even play it !!!!!!!!!!!!!

 

[fighter997]

yup im getting the same problem. this is the 3rd problem so far and i am not planning to giv up yet, and guess what, i havent played yet!!!

 

[Mictlantecuhtli]

Pick an older driver from here: http://www.nvidia.com/object/winxp-2k_archive.html