I have both sata dvd and hdd. Everything has been fine until I first updated to 10.5.5. After reboot i just got still waiting for root device. Tried to install ideneb 10.5.5. Installation went smooth, but after restart I just get the root device message. Right after the firewire security mode message. Any suggestions? Asus p5kse motherboard. Ide disabled.

You need to make sure SATA kexts are loaded... if you are stuck use a windows partition and mac drive application to load the kext to you mac partition or HDD for sata to work.
AppleIntelPIIXATA.kext should be the one to enable ICH-X sata (X being what ever number ICH your sata is) you could try overwriting appleahciport.kext & ioatafamily.kext. but i think the first one is your main problem.

Another thing keep you important sata kexts in a folder back-up somewhere and everytime you update replace incase that's what i do.

Hope this helps

Thanks! I found out that AppleIntelPIIXATA.kext is in the IOATAFamily.kext. So I booted from a kalyway 10.5.2 dvd, and started terminal. Copied IOATAFamily.kext & IOAHCIFamily.kext (don't know why I used the last one really... ) from a usb stick to System/Library/Extensions/ Booted with -f -v and everything worked out!! Thanks!!

I HAVE THE VERY SAME PROBLEM. Canyou please clarify - did you use the kexts from the 10.5.2 dvd or did you have it on usb stick from elsewhere??? Pleaseeeeee, I am stuck on this SATA problem!!!