athlon 64, 1 gig ram, 128mb 9600 = bad for gaming?

I rescently purchased a Time Platina laptop which is running an athlon 64 3200+ (2 ghz), 1 gb ram, and a 128mb dedicated ddr ati radeon mobility 9600 AGP 8x. The preinstalled OS is windows home SP1.

When i decided to test several games (comparing the performance to my brothers laptop, a compaq presario r3000t with a 2.4 ghz P4, 512mb ram and a 64mb dedicated ddr 9200 ati radeon), i noticed that some games were faster, but also had some odd problems...

Need For Speed Underground: The 1 second freeze at the start of races and the small jerks on the first lap of the race (apparently because the ysystem is stil loading the level), which happen on EVERY 32 bit system ive played it on, are gone, but the game slows down in several random places throughout the race... ie, the game will suddenly run at half the speed, cars slow down masively for a second, then shoot off again (this is not jerk caused by lower FPS rates)

Jedi Knight III: as i understand it, this game uses the quake 3 engine and runs in opengl. Witht he same settings as on the P4 laptop (which gives a solid frame rate, usually around 50, drops to about 25 in some places), it runs awefully. lightning and shadow effects dont work, even with verticle sync on, polygons slice vertically, and average fps is around 20 throughout...

I have heard rumours that athlon 64 bit processors have various problems with opengl, and that 64 bit support has not been added to ati cards, so performance may vary.. could this be the reason for these problems?

The radeon drivers for this mobile card are dated 12/08/2003... and tiny do not update their drivers... but i have installed the latest omega drivers for the card, which are based on the latest ati catalyst drivers, and this has improved performance a bit, but jedi knight 2 and 3 still run horribly.

Any advice would be much appreciated, thanks a lot