Ok, getting more experienced here I did some nice cleanup to my code. I managed to get my 100+ line controller to around 30 :-)
I decided to generate new tables for every user. Instead of filtering one huge tabe. The forst time I load the page everything seems fine, although I'm missing the add edit etc buttons. Then I pushed the Export button and I get the aforementioned error. Now every time I reload the page,since I have table_token defined the call to smartgrid generates this error. Here is my controller: def index(): if session.table_token is None: if auth.user: session.table_token = db.budgets.last_opened user = auth.user.first_name else: session.table_token = filter(lambda x: x.isalnum(), str(uuid.uuid4())) user = 'Guest' db.define_table(session.table_token + '_accounts', accounts) db.define_table(session.table_token + '_transactions', transactions) grid = SQLFORM.smartgrid(db[session.table_token + '_transactions']) return dict(user=user,grid=grid) accounts and transactions are db.Table objects which were previously defined. Any help is kindly appreciated