There should be some confilict between form-manager and other plugins. I have met this situation when I installed the Jquery-updater plugin. After uninstall this plugin and reinstall the form-manager, it works for me.
you need to read this:
fm_summary_get_item_label($nickname) – get an item’s label by nickname.
fm_summary_get_item_value($nickname) – get an item’s value by nickname.
see http://www.campbellhoffman.com/question/customize-the-e-mail-notifications/
