[CentOS] intel video driver

Hi all.

I just installed centOS 5 on a new pc and everything works very well, 
apart the video driver that is not recognized by X and so I get no 
graphics hardware acceleration (glxgears is very unresponsive).

lspci reports:
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core 
Processor Family Integrated Graphics Controller (rev 09)

while Xorg.0.log reads:
(--) PCI:*(0:2:0) Intel Corporation unknown chipset (0x0102) rev 9, Mem 
@ 0xe0c00000/22, 0xd0000000/28, I/O @ 0x3000/6

I've been searching for an rpm for adding the right driver with no success.

Could anybody try to help me out, please?
Thank you.
Robi