Hmmm, for some reason I misread your problem as being with SATA, not with SCSI. I suspect that it's in the same type of thing, though, since it happened around 2.6.18, so I'm leaving my original post here. Make sure that CONFIG_SCSI hasn't been removed from your .config file.
Original:
They made a pretty serious change after 2.6.18 that affects only /dev/sdx devices. Look in your .config file and change all occurrences of "CONFIG_SCSI_SATA" to "CONFIG_SATA". Do not change "CONFIG_SCSI" as that is a valid name.
Or, you can do it this way and then recompile/reinstall:
http://www.linuxquestions.org/questi...7/#post3540344