the checksum is correct and im going to guess it IS just the kext. I'm going to try and use the one from 10.5.1 and see if this helps with my initial issue of it giving me that "SAM media read or write failed" message.

Where are they located on the DVD disc?

ok, yea i tried that and it gives me an immediate kernal panic. so i need to somehow edit these kext and find out whats in 10.5.1's kext that allows me to get to the installation program, then add it to 10.5.2's extensions.mkext.