no autocompletelist is shown

[geoang]

hi
using the following Markup and codebehind i'm not able to see the autocompletelist:

<TextBox x:Name="txtSearch" 
                 TextChanged="TextBox_TextChanged" 
                 behaviors:AutoCompleteBehavior.AutoCompleteItemsSource="{Binding AutoCompleteList}"                 behaviors:AutoCompleteBehavior.AutoCompleteStringComparison="InvariantCultureIgnoreCase"
        />

Private pList As New List(Of String)
    Private Property AutoCompleteList As List(Of String)
        Get
            Return pList
        End Get
        Set(value As List(Of String))
            pList = value
        End Set
    End Property

AutoCompleteList is updated on textchanged of the textbox by calling a search-index.

what am i missing??

best regards
george