C# - Item In RadioButtonList Not Firing SelectedIndexChanged

I have a table cell with a RadioButtonList. When each item is selected, the SelectedIndexChanged event is supposed to fire so the app can populate a related listbox. The problem is it stopped working. Now if I selected the first entry 'Division', the event never fires. I put a break-point on the event handler and it gets called for the other entries but not for Division. I'd believe it if some other code is interfering, I just don't know where to start looking.

[update] By not working, I mean if you selected Item #2, the update works; then if you select Item #1 it doesn't. If I change where the 'Division' item appears in the list, it still has the problem. Is there something in the page load cycle that could be aborting the event handling chain?

private TableCell foo()
{
hierarchyLevel = new RadioButtonList();
ListItem DivisionItem = new ListItem();
DivisionItem.Text = "Division";
DivisionItem.Value = "afe_dvsn";
hierarchyLevel.Items.Add(DivisionItem);
ListItem DistrictItem = new ListItem();
DistrictItem.Text = "District";
DistrictItem.Value = "afe_dist";
hierarchyLevel.Items.Add(DistrictItem);
ListItem AreaItem = new ListItem();
AreaItem.Text = "Area";
AreaItem.Value = "afe_supt";
hierarchyLevel.Items.Add(AreaItem);
ListItem ForemanItem = new ListItem();
ForemanItem.Text = "Foreman";
ForemanItem.Value = "afe_frmn";
hierarchyLevel.Items.Add(ForemanItem);
ListItem AfeCodeItem = new ListItem();
AfeCodeItem.Text = "AFE Code";
AfeCodeItem.Value = "afe_code";
hierarchyLevel.Items.Add(AfeCodeItem);
ListItem PropertyItem = new ListItem();
PropertyItem.Text = "Property";
PropertyItem.Value = "prop_sub";
hierarchyLevel.Items.Add(PropertyItem);
TableCell cellforHierarchyLevel = new TableCell();
cellforHierarchyLevel.ID = "hierarchyLevel";
cellforHierarchyLevel.Controls.Add(hierarchyLevel);
hierarchyLevel.EnableViewState = true;
hierarchyLevel.AutoPostBack = true;
hierarchyLevel.SelectedIndexChanged += new EventHandler(hierarchyLevel_SelectedIndexChanged);
return cellforHierarchyLevel;
}