Inherited properties are not editable in designer

I have a base form class that is providing a new property that looks Like this

Public Class BaseForm

    Private _HappyTime As Boolean

    Public Property HappyTime() As Boolean
        Get
            Return _HappyTime
        End Get
        Set(ByVal value开发者_Go百科 As Boolean)
            _HappyTime = Value
        End Set
    End Property

End Class

<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Class BaseForm
    Inherits System.Windows.Forms.Form

    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        Try
            If disposing AndAlso components IsNot Nothing Then
                components.Dispose()
            End If
        Finally
            MyBase.Dispose(disposing)
        End Try
    End Sub

    Private components As System.ComponentModel.IContainer

    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        components = New System.ComponentModel.Container
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.Text = "BaseForm"
    End Sub
End Class

Now when I inherit the BaseForm on a new form, the HappyTime property displays in the properties window as false, and is uneditable.

I've recreated this BaseForm and Inheriting Form in an entirely new soloution and, the HappyTime property is editable and works as expected. For some reason in the existing project (where these changes need to be made) it's not behaving properly.

This leads me to believe that it has something to do with the configuration of my project. Does anybody have any insight into this, short of creating a new project and moving all the code into it?

Environment Information: .Net Framework 3.5, Visual Studio 2010, Win7 x64

In the recreated solution, is the _HappyTime property Private or Protected? I think that if you just change it to Protected in this solution, it'll work.