Error icon in datagrid

[oakleaf]

Writing my own update statements for a fairly complex datagrid. When running my insert/update/del statements I get "parameter ?_5 has no default value." in the error icon on the left next to each modifed record, and no updates are performed. Trying to understand what field ?_5 is in the whole scheme of things. Field in dataset, field in SQL statement, what.. and how to make the error become more understandable...like change it to display the field name? thanks for any help or ideas..