NFS Underground doesnt start!!!

Hi!
Ive just got NFS Underground but it dont start
ive installed the latest driver for my grafikcard and direct x 9.0b
ive got a ATI Radeon 9800 Pro
when I start i see the loading screen blinking fast
the mouse is frozen and i only can close it with the taskmannager
what is the problem?

P4 3.0Ghz 800Mhz FSB
Asus P4P800 deluxe
1Gb Ram


please help!