Look like the contacts in W-T tumbler are not working. I got the same problem. Zoom reset could be switched off from setup - in M mode pres setup; go to tools (left & down); go to "Zoom Resume" (8 downs); set to OFF.
Now when you turn camera ON there will not be a display of resuming the Zoom.
ZOOM function is not working if you set a conversion mode - in M mode pres setup; go 2 up; check setup mode. If it is "OFF"set it to one of other positions and watch the lense. If lense move, when you changing CONVERSION, this means your ZOOM mechanics e.g. motor etc. is working and the only posible culprit for ZOOM not to work is the switch (contacts dirty I presume).
Don't know how to get to them for now, Still looking for clues.
George, January 2010