10.6.8 update AMD, Legacy Kernel?

so i have 10.6.2 installed everything works except my video card which i need to replace, anyways i tried updating from 10.6.2 to 10.6.8 and my computer wouldn't boot, do i need to install the AMD & Legacy kernel .pkgs i installed on the original first install??

the only things i installed from the cd where
10.6.2 Update
Legacy Kernel
and AMD

im running an Emachines T3410
AMD Sempron 3400+ Processor
1.2 Ram
128 MB NVIDIA GeForce 6100

http://reviews.cnet.com/desktops/emachi ... 32962.html

any help is appreciated