[web2py] SQLFORM.grid search using signature

[Gian Luca Decurtins]

Hi all

I can't perform search operations on SQLFORM.grid forms. If I remove the 
"@auth.requires_signature()" part, it does work.

In the webserver-logfile I noticed that the edit page is signed, while the 
search page isn't.
EDIT: 
/init/location/form/edit/location/4?_signature=368187847e306b826b2c5a1f8a4780c236aafb8c
SEARCH: /init/location/form?keywords=test

Given the following code in controller location.py:

@auth.requires_signature()
def form():
    db.location.id.readable=False 
    query=((db.location.id > 0 ))
    default_sort_order=[db.location.country]
    form = SQLFORM.grid(query=query, orderby=default_sort_orderr,
                create=True, deletable=True, editable=True, 
user_signature=True)
    return dict(form=form)


What do I have to do to get it working?

Regards
-Gian.