[web2py] value not displayed in custom widget

[apple]

I want to show a notes field as a text box using a custom widget. In
my edit form I can see the notes field, type in a value, click submit
and the database is updated correctly with the new value. However when
I reopen the edit form the text box shows as empty.

Am I missing something or is this a bug?

My model code is:

def fullwidthwidget(field, value):
    return TEXTAREA(_name=field.name,
                 _id="%s_%s" % (field._tablename, field.name),
                 _class=field.type,
                 _value=value,
                 _style="width:100%",
                 _rows="3",
                 requires=field.requires)

and in the define table:

Field("notes2", 'string', widget=fullwidthwidget),