First, thanks for doing this.  

I've had the original post bookmarked for quite some time (years, it seems) with plans to implement, and this simplifies the process quite a bit.  Performance is much better than rsync-over-autofs-smb (for any number of reasons).

5) I got a passing error message from the at one stage, and would suggest the following change:

if [ ! -z $xferOK ] && [ $xferOK-eq 1 ]; then
Basically, if xferOK is not set, then [ $xferOK-eq 1 ] generates an error (and does not match), with my change it will not generate an error, and will still not match.

I ran into that error " line 10: [: -eq: unary operator expected" as well - even on successful runs.  It looks like $xferOK is never declared, but is just passed in.
$WINEXE -U $UNAME -W $WRKGRP --password=$PWD //$BOX 'cmd /c echo '1' > c:\backuppc\wake.up' <&-
echo "Rsync and shadow copy unloaded"
if [ $XFEROK -eq 1 ]; then
   if [ -f $WOLDIR/$BOX.state ]; then
      read wasoff < $WOLDIR/$BOX.state
      echo -n "State before backup: "

Thanks for all your work on this!

-Kris Lou