I have a few webcombo boxes that are hierachial:

Continent Country

When the form loads everything works fine, when I change the continent the first time, the country repopulates correctly. However if I change the continent a second time I receive an error:

Specified argument was out of the range of valid values.Parameter name: The DataValueField of ValueField was not found in the Columns collection. 

Can anyone tell me why?

P.S. This is all I have in the Page_Load event

            if (!IsPostBack)
        {
            this.Load_AreaList();
            this.Load_AreasOfInterest();
            this.Load_Degrees();
            this.Load_GenderList();
            this.Load_ParticipationDateModifiers();
            this.Load_ProgramCategories(nEventID);
            this.Load_YesNoList();
            this.Load_ParticipantInformation(nParticipantID); 
        }