GeForce 4 TI DOES NOT support DirectX 9. People think just because DX9 is on their system, they are making full use of it, even on Integrated Graphics. This is NOT true whatsoever. The only video cards out now to fully support DirectX 9 is the GeForce 6 series.
Games are just getting into an era where DirectX 9 is needed, in fact, DX8.1 games are still being released all the time. For example, BF2 only uses DX8.1 for its visual effects, although it does use DX9 on Nvidia cards to improve performance. Get a 6600GT or 6800GT, best bang for the buck.