sb450 - Low speed reading HDD

[ipotex]

Hi! Finally I can install Leopard 10.5.1. Really Thanks!
I fix a ps2 keyboard and mouse problem copy kext from DVD.
Now, I have problem with my HDD. Reading/Writing speed 1mb/seg.

This is my mother. RS482M4-ILD
http://www.msicomputer.com/product/p_spec.asp?model=RS482M4-ILD

I see for Tiger kext for fix it, but i dont know if exists for Leopard.
Thanks!

Gaston