Problems Displaying Forms

[Chris Quick]

I am creating an application that will create a notify window similar to outlook 2003 notify popup. I am making an asyncronous remoting call using system.thread that raises an event to show the form. However, the form shows up as a black box and then immediately disappears when the event is called. If I call the function through a menu item or button, it works fine. Here's the popup code:

Private Sub ATU\_RetrieveDone(ByVal e As AsyncUpdater.AsyncUpdaterEventArgs) Handles ATU.RetrieveDone
    Me.UpdateTimer.Enabled = False
    If e.Forums Is Nothing Then
        UpdateTopicListView(e.Results) ' Updates a list view and 
                                       ' displays the popup.
    Else
        UpdateForumListView(e.Forums)
    End If
    Me.UpdateTimer.Enabled = True
End Sub

Private Sub UpdateTopicListView(ByVal Topics As ResultsCollection)
    For index As Integer = 0 To Topics.Count - 1
        ...
    Next
    Dim Message As String
    Message = "{0} new topic updates have been retrieved from {1}"
    Me.ShowPopup(String.Format(Message, Topics.Count, ClientSettings.WebURL))
End Sub


Private Sub ShowPopup(ByVal Message As String, Optional ByVal TimeOut As Integer = 0)
    Dim displaytime As Integer
    If TimeOut < 1000 Then
        displaytime = ClientSettings.PopupTime \* 1000
    Else
        displaytime = TimeOut
    End If
    Dim PW As New PopupWindow
    PW.SetProperties(NewMessagePopup.Blend, Message, displaytime)
    PW.ShowPopup()
End Sub

And here's routine that creates the popup using a seperate windows form.

Public Sub ShowPopup()
    Dim tbl As TaskBarLocation
    Dim workingArea As Rectangle
    Dim pt As Point

    pt = New Point
    pt.X = 0 : pt.Y = 0

    workingArea = SystemInformation.WorkingArea
    tbl = GetTaskBarLocation() ' Gets an enumerator 
                               ' indicating the windows task bar 
                               ' location.

    Select Case tbl
        Case TaskBarLocation.Bottom
            pt.X = workingArea.Right - Me.Width
            pt.Y = workingArea.Bottom - Me.Height
        Case TaskBarLocation.Left
            pt.X = workingArea.Left
            pt.Y = workingArea.Bottom - Me.Height
        Case TaskBarLocation.Right
            pt.X = workingArea.Right - Me.Width

[Chris Quick]

I've done some more research and it appears the problem is caused using timers. I've used both System.Timers.Timer and System.Windows.Forms.Timer and both give the same result, a black box that appears and then disappears. If I call the ShowPopup subroutine by clicking a button, it displays correctly. If the timer causes the form to be displayed, I get the black box. Here's the logic steps used: 1) Timer.Tick event occurs 2) Tick Handler creates a new AsyncUpdater and invokes the GetUpdate method 3) GetUpdate creates a new thread and begins the remoting call 4) Once GetUpdate has completed the remoting call, the event RetrieveDone is raised. 5) The main form handles the event causing a list view to update it's list of items. 6) The ShowPopup method is called to display the popup. Any help or ideas would be greatly appreciated. I can't understand why the manual invoking (pressing a button) works but the event handler doesn't. Thanks!