PK int autoincrement

Category varchar(50)

ProcCode char(5)

Procedure varchar(50)

Unfortunately, this table is poorly designed but I can't change it.  The Category field is NOT unique and can in fact be the same for many rows.  I created a business object for this table along with a maintenance form with all the controls bound to an instance of the BO.  The Category control is a combobox with the dropdownstyle set to dropdown (the default).  I created a method in the BO to return a datatable of the distinct Category values in the table and used it to populate the combobox control.  The Display and Value Members of the combobox are both set to the Category field.  All rows display fine when I navigate through them but if I try to add or edit a row, the textbox portion of the combox control is not editable.  In other words, I must make a selection from the entries the the list portion of the control.  I need to have the user be able to enter a new category in the combobox control.  I thought the dropdownstyle = dropdown allowed this or am I missing something?

Thanks!!