Maybe there is a problem in wizard or in your rml file you are using data to fetch desired values, try to just print [[ data ]].If it does not print anything,then there is a problem in wizard. Are you generating report by wizard? Because if you generating report by wizard, the wizard method returns the dictionary of the following keys & values : Suppose wizard method is like this,

def print_report(self, cr, uid, ids, context=None):
        """
         To get the date and print the report
         @param self: The object pointer.
         @param cr: A database cursor
         @param uid: ID of the user currently logged in
         @param context: A standard dictionary
         @return: return report
        """
        if context is None:
            context = {}
        datas = {'ids': context.get('active_ids', [])}

        res = self.read(cr, uid, ids, ['employee_ids',  'date_from', 'date_to', 'salary_on'], context=context)
        res = res and res[0] or {}
        datas['form'] = res
        datas['ids'] = res.get('employee_ids',[])
        return {
            'type': 'ir.actions.report.xml',
            'report_name': 'year.salary',
            'datas': datas,
       }

In datas we have passed employee_ids, datas must consists list of ids. Maybe this will help you.

Hello again does not work if I press the preview button in the page header company information same if I new database, use OpenERP 7 with the latest nightly build

thanks