[web2py] ValueError: need more than 1 value to unpack

[Kostas M]

I am trying to reproduce the "What is going on with web2py?" video
(http://vimeo.com/13485916). At the 'friend' section, when I try to
enter a new friend eg. "Max" I am getting this error:

Traceback (most recent call last):
  File "C:\Temp\web2py\applications\myplayepedvm/models/
plugin_wiki.py", line 597, in render_widget
  File "C:\Temp\web2py\applications\myplayepedvm/models/
plugin_wiki.py", line 183, in create
  File "gluon/tools.py", line 2874, in create
  File "gluon/tools.py", line 2817, in update
  File "gluon/sqlhtml.py", line 987, in accepts
  File "gluon/html.py", line 1557, in accepts
  File "gluon/html.py", line 558, in _traverse
  File "gluon/html.py", line 558, in _traverse
  File "gluon/html.py", line 558, in _traverse
  File "gluon/html.py", line 558, in _traverse
  File "gluon/html.py", line 565, in _traverse
  File "gluon/html.py", line 1336, in _validate
  File "gluon/validators.py", line 490, in __call__
ValueError: need more than 1 value to unpack



meta-code is:
db.define_table('friend',Field('name',requires=IS_NOT_IN_DB(db,'friend_name')))

Home is:
# Test App
## Friends
``
name: create
table: friend
message: new friend
``:widget
Friends:
``
name: jqgrid
table: friend
col_width: 80
width: 700
height: 100
``:widget