[web2py] ('str' object has no attribute 'update_record')

[reyelts]

I think I found another issue with upgrading from 1.81.4 to 1.91.4. My
code that updates table entries craps out with the subject exception.
I'm just doing the normal update_record as described in the book:

       elif form.accepts(request.vars,session,dbio=False):
         del form.vars['button']
         now = datetime.datetime.now()
         form.vars['PS_timestamp_updated'] = now
         if not PSDBrec:
            form.vars['PS_id'] = auth.user.id
            form.vars.id = db.PSDB.insert(**dict(form.vars))
            session.flash = 'measurement create complete'
         else:
            PSDBrec.update_record(**dict(form.vars))   <<<<<<<<<<
exception flagged here
            session.flash = "measurement edit complete"
         db.commit()
         redirect(URL(r=request,c='default',f='index'))
      elif form.errors:
         response.flash = 'measurement form has errors'

The variables section of the error ticket is interesting. It shows
PSDBrec.update_record as "undefined":

   Variables
   PSDBrec      '1'
   form.vars    <Storage {'PS_estimated_activity': 0.0,
'PS_skin...old_triceps': 0.0,    'PS_circumference_hips': 0.0}>
   builtindict  <type 'dict'>
   form <gluon.sqlhtml.SQLFORM object at 0xaf8947ec>
   PSDBrec.update_record        undefined