i am actually using the generic pc image.
i'm at work so i don't have access to my box, but i believe from some of the
list messages and email i received last night has shed some light on my
problem and a possible solution...

my cf card is mounted as /dev/ad2, but the mount failure messages states
that there is no /dev/ad0a. i do not have any way of actually editing the
/etc/fstab file, but it seems to me that it is simply a matter of moving the
card to the primary IDE channel, instead of the secondary IDE channel where
it currently lives.

thanks for all your help and comments, i'll let you know how it goes
tonight!
steve