Running Visual Studio 2010/.NET 4.0/Infragistics Suite 10.2.
WebHierarchicalDataGrid defined with only ID, runat, height, showfooter, and width in the .aspx file.
I have a system.data.dataset defined with a few datatables and relations.

Set IniitalDataBindDepth = 0, InitialExpandDepth = 0, DataMember, Datasource, AutoGenerateBands = true, AutoGenerateColumns = true and then call Grid1.DataBind and the web form works showing the arrows so I can drill down into child rows, click on them, they do the post back, and everything works.

IF, however, instead of doing AutoGenerateBands and AutoGenerateColumns (set both to false), I fill in the Bands and Columns information through code, the page displays okay initially.  When I hit one of the arrows to drill in, however, I get:
   [InvalidOperationException]: LoadViewState_Exception with a huge stack trace.  See attached screenshot of the error.

Help???