Looking at the .config file produced by gentoo-sources-2.6.22-r2, I see a line: CONFIG_SCSI_WAIT_SCAN=m If I edit the .config file manually to turn it off (or even remove the line altogether), it comes right back as soon as I do a make config or make menuconfig (even if I completely turn off all SCSI support in the kernel). Very strange, and something that I don't think should happen.
http://lkml.org/lkml/2007/5/13/75