I ported my drupal 6 site to D7 successfully. Everything is working fine except the page manager component of ctools. When I enable Page Manager, my administrative tasks vanish and displays the error

You do not have any administrative items.

I tried the solutions suggested for such errors but nothing helped to make it work. I am unable to take any of the administrative tasks except modules page.
The dblog shows this error when ever I get the above mentioned message:
PDOException: SQLSTATE[HY000]: General error: 1366 Incorrect integer value: '' for column 'weight' at row 14: INSERT INTO {menu_router} (path, load_functions, to_arg_functions, access_callback, access_arguments, page_callback, page_arguments, delivery_callback, fit, number_parts, context, tab_parent, tab_root, title, title_callback, title_arguments, theme_callback, theme_arguments, type, description, position, weight, include_file) VALUES (...

I ported the site twice but error persists.

Please help solving the issue and let me know if this has nothing to do with ctools.