for proper boot on older machines you need to boot with this flag "npci=0x2000", also letting you see what behind the verbose.
for dsdt loading you can write an entry in com.apple.boot.plist for for dsdt location, although it supposed to load by itself when on Root of partition or Extra dir.
note that if you can boot from usb but not from hard drive then you are doing something wrong
yeah i added that to my com.apple.boot.plist and same thing, but i was thinking the same thing ;how i can boot from usb but not from my drive. It's weird cause i think my dsdt is causing the problems but its the same one i was using from snow leopard, is there anything i need to edit? but maybe you can shed some light, my specs are
motherboard:msi p55 cd53
cpu=i5 750 2.6
ATI xfx radeon 4850 video card.
250gb sata drives.