The aic7xxx needs a patch to bring it up to version 5.1.31. This version fixes problems with scsi devices like external Zip100 drives. I don't know all the details, but I know that my drive wouldn't work when I upgraded my 6.2 kernel to kernel-2.2.16-3 from the RedHat errata. I suggest you add this patch to your kernel SPEC file (you want to apply it after `%patch107 -p1').
Created attachment 5565 [details] aic7xxx 5.1.31 update