I'm seeing a rather bizarre behavior when implementing the theme selector control and the setinputcontrolshightlight function from chapter 2. When the page loads and I click on the theme selector dropdownlist, it is automatically posted back (before allowing me to select a value). However, if I tab into the dropdown list, it work fine (including the highlighting) and posts back after I select the value. Has anybody seen this issue? Any ideas of how I can correct it?

Here is my code:
______________________________________________
<%@ Control Language="VB" AutoEventWireup="false" CodeFile="ThemeSelector.ascx.vb" Inherits="menichols.UI.Controls.ThemeSelector" %>
<b><asp:Label runat="server" ID="locTheme" Text="Choose Theme: "></asp:Label></b>
<asp:DropDownList runat="server" ID="ddlThemes" AutoPostBack="True" />
------------------------------------------------------------
Imports menichols
Imports menichols.UI

Namespace menichols.UI.Controls
    Partial Class ThemeSelector
        Inherits System.Web.UI.UserControl

        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            If Globals.ThemesSelectorID.Length = 0 Then
                Globals.ThemesSelectorID = ddlThemes.UniqueID
            End If

            ddlThemes.DataSource = Helpers.GetThemes()
            ddlThemes.DataBind()
            ddlThemes.SelectedValue = Me.Page.Theme

        End Sub
    End Class
End Namespace

---------------------------------------------------------
BasePage
---------------------------------------------------------
Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
            Helpers.SetInputControlsHighlight(Me, "highlight", False)
            MyBase.OnLoad(e)

        End Sub

Protected Overrides Sub OnPreInit(ByVal e As System.EventArgs)
            Dim id As String = Globals.ThemesSelectorID

            If id.Length > 0 Then
                Dim profTheme As ProfileCommon = HttpContext.Current.Profile
                ' if this is a postback caused by the theme selector's dropdownlist,
                ' retrieve the selected theme and use it for the current page request
                If Me.Request.Form("__EVENTTARGET") = id AndAlso _
                        Not String.IsNullOrEmpty(Me.Request.Form(id)) Then
                    Me.Theme = Me.Request.Form(id)
                    profTheme.Preferences.Theme = Me.Theme
                Else
                    ' if not a postback, or a postback caused by controls other then the theme selector,
                    ' set the page's theme with the value found in the user's profile, if present
                    If Not String.IsNullOrEmpty(profTheme.Preferences.Theme) Then
                        Me.Theme = profTheme.Preferences.Theme
                    End If
                End If
            End If

            MyBase.OnPreInit(e)
        End Sub
---------------------------------------------------------------
helper.vb
---------------------------------------------------------------
 Public Shared Sub SetInputControlsHighlight(ByVal container As Control, ByVal className As String, ByVal onlyTextBoxes As Boolean)
            For Each ctl As Control In container.Controls
                If (onlyTextBoxes AndAlso TypeOf (ctl) Is TextBox) OrElse TypeOf (ctl) Is TextBox OrElse TypeOf (ctl) Is DropDownList OrElse _
                 TypeOf (ctl) Is ListBox OrElse TypeOf (ctl) Is CheckBox OrElse TypeOf (ctl) Is RadioButton OrElse _
                 TypeOf (ctl) Is RadioButtonList OrElse TypeOf (ctl) Is CheckBoxList Then
                    Dim wctl As WebControl
                    wctl = CType(ctl, WebControl)
                    wctl.Attributes.Add("onfocus", String.Format("this.className = '{0}';", className))
                    wctl.Attributes.Add("onblur", "this.className = '';")
                Else
                    If (ctl.Controls.Count > 0) Then _
                        SetInputControlsHighlight(ctl, className, onlyTextBoxes)
                End If
            Next
        End Sub