Boot Camp 2.1 update problem

Hi, straight to the point as i need the answer very urgently, so please help me if possible.

okay, i just purchased unibody MBP. that came with Leopard of course.
and then i use the built in boot camp application to install my copy of windows XP SP2, eerything went well.
then i insert the CD that come with my MBP to install the boot camp driver on it.
long story short , it works well and no problem at all.

then i decided to upgrade my xp to SP3 using the online update service.
after several reading on this forum, i found out that i must install boot camp 2.1 driver before installing XP SP3 to avoid any problem.

im not sure what version of boot camp that are contain on the OSX leopard CD that come with my MBP so i downloaded the boot camp 2.1 from apple.com instead, just to make things sure.

and then i restarted my machince and went into my windows partition, installed the boot camp 2.1 that i've downloaded, and it says 2 options, remove / update, so i klik update, and it says operation sucsessfull and it aksk me to restart, and i restarted,
again evertyhting went well witouht any error.

i turn it on again and to make sure i have the latest boot camp version i clikc the apple software application on my windows XP. and it says i don't have any update so i guess i have the latest verion of boot camp then.


but the problem is
all my function keys are not working, f1/f2 for brightness, f10-f12 for volume and etc, it works as "f" keys but not as function keys, and i've tried pressing them together when i pressed the fn key and still it don't work, and also volume are not working either, i have no sound at all from my windows XP.

it's weird cause all of that are working fine when i use the built in boot camp drier from my leopard CD, before i upgraded to the so called boot camp 2.1 that i downloaded from apple.com

so please anyone can help me now ?

i really need to install SP 3 for it's added protection and where did i went wrong ?
should i install the boot camp driver again to overwrite the 2.1 that i've downloaded ?