I have a DataGridView bound to a DataSet, the DataSet contains a primary key column of type VARCHAR(16) and one other column of type TEXT. In this instance the primary key column is actually to be editable by the user, it is not an identity column, and doesnt have a default value.

When I go to insert a row on the DGV I fill out the value for the PK column, and I put some data in the TEXT column, however, when I press tab to drop off the row and "insert" it, i get "Column * does not allow nulls" and then the new row disappears.

Any clue as to how I can fix this, the column is definitely not empty, and it's not violating a unique constraint, so I am unsure why its throwing this exception.

I have been googling for a while, I set the AllowDBNulls property on the DataSet column but that didnt work either. 

Luke

The DataSet is generated from an SqlDataAdapter, I use FillSchema, and then Fill.

The DataSet also contains relations, the table I am having problems with is a child of a parent table, the relation exists for the Parent to Child relationship.

Luke