/bin/sh: permission denied -- fstab error?

[David Piniella <dpiniell@newssun.med.miami.edu>]

I'm getting a ton of "/bin/sh:Permission Denied" errors on everything 
that /etc/init.d/rcS calls -- both on  bootup and shutdown. The errors 
are along the lines of
/etc/init.d/rcS: /etc/rcS.D/S70xfree86-common: /bin/sh: bad interpreter: 
Permission Denied"

when I boot into a gnoppix live CD and mount /dev/hda1 as /mnt/hda1 and 
chroot /mnt/hda1 and run /etc/init.d/rcS I still get the same errors, 
even though mount tells me that /dev/hda1 is mounted as rw. I thought 
that maybe /bin/sh could have become corrupted, so I copied over a new 
/bin/sh from the gnoppix CD onto /dev/hda1's /bin/ dir but still no luck.

any suggestions?

my hda1 line in /etc/fstab is
/dev/hda1   /           ext3         users,auto,errors=remount-ro   0     1

should I change fstab?

why is hda1 being mounted ro ? (and more importantly, how do i get it to 
stop?)

I tried googling for this but did not find anything useful; #debian on 
irc.debian.net was also no use this time. any suggestions would be 
appreciated. The man and info pages for fstab state that rw is the 
default, so I've left "rw" out of the options field in fstab.

-d.