I have tested this on a 230 and it does work there.  So it would
seem that the 140 and 170 are out though.  One way to tell is to
go and open the PowerBook control panel(7.1).  There is a setting
there that allows you to set the time to wake up the Mac.  If it
is present when you open the control panel, then you can assume that
SetWUTime will work.  
