Toggling Panel Visibility Isn't Working When They Are Stacked

I have a form that has two views. These views are controlled by radio buttons on top of the form.

Here is the program:

Notice how the Radio button for Number Converter is selected.

Here is what it looks like when you select the Text Converter radio button:

That isn't right. I have it set to hide the panel containing the number converter and show the one containing the text converter when you click that one. It hides the number converter but doesn't show the text converter.

Here is a picture of the text converter panel:

Here is the relevant code:

Private Sub frmCalculator_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
rdoNumberConverter.Checked = True
End Sub

[Code]....