Dell 1450 and D-link 774b

I will say i am sorry if this problem has already been brought up, but with my experience, i can not make my laptop connect to the router in the a channel (the router has Tri-mod a/b/g)

I tried to install drivers for Dell 1450 and firmware for my router. Upgrading firmware seems pretty easy, while upgrading driver drives me nut. I try to use the newest driver i found on Dell, which is A03 - updated in 5/13/2004. But no matter how i tried, the driver is still updated to 9/4/2004

Does it make a difference between these two drivers? Is it right that if i upgrade it, my a channel will work on my laptop?

BTW, i have i8600c

Thanks to any response