here's my spec:

amd X2 3800+ over-clocked to 2.3Ghz
nvidia 9600GT 512MB
4G ram
windows 7 32bit.

same spec worked perfectly fine with fallout3 and TES:Oblivion but for new Vegas, i only get around 20fps when i hang around in good spring or when talking. the fps in rooms or dungeons

i think i meet the minimum system requirement for this game but obviously i wont be able to play under such fps status. is this is a bug or i should upgrade my computer??

Look into the http://www.gamesas.com/index.php?/topic/1134379-d3d9dll-and-why-it-works/ (there are several threads about it). It will most likely sort your fps issue.

Download link from Nexus is near the end of the first post in the topic linked above.

hey pal!! you saved my life!