Panel set to autoscroll is too limited

[!NoItAll]

I am using a panel control in vb.net (2010) to build a timeline of images. These are very small images (320x180) and I am running into a limit of 240. While the panel does not complain when I add more - it will only scroll to the 240th one.
Here is what my timeline looks like:

mouse-over to see the whole thing...

My question is: Any ideas on how I can do this? I am counting on some of the built-in functionality of the panel in autoscroll mode (being able to bring any of the thumbnails into view), etc. I am certainly not averse to purchasing a third party control for this. I really need to be able to display 1000 or more thumbnails!
p.s. the image itself is hosted in a small custom control that I made... perhaps this just uses too much memory...??

[Rabbit]

You could use a paging type solution instead of a scroll.

[!NoItAll]

Hmmm - that actually makes me think the problem may be a limit on the width of the window rather than anything else. Your suggesting may work if I just add another row below the current one. The normal user metaphor for this kind of thing is a left-to-right timeline, but a real timeline doesn't typically show every frame so some deviation from that might be appropriate...
But - just in case, does anyone know about a 3rd party control that might do the trick?

[!NoItAll]

Ok - found the answer. The problem is that the panel control will not allow you to set the .left value of any child objects to anything greater than 32767 (short). I have no idea why this is. If you set it to anything larger it will just ignore you and reset it to 32767. So as I built my timeline all of my thumbnail windows that needed to go beyond a .left of 32767 were getting plopped on top of each other.
The answer was to NOT use the panel control, but to create my own container made of system.windows.forms.form. It required a little setup, but that was relatively easy and straight-forward. Here is a test harness I created to make it work:

Imports WXC
Public Class Form1
    Private WinHost As New System.Windows.Forms.Form
    Private tWin() As WXC.ThumbnailWindow
 
 
    Private Sub MakeTimeline()
 
        'size and position the host window
 
        With WinHost
            .TopLevel = False
            .Visible = False
            .Parent = Me
            .Left = pnltl.Left + 2
            .Top = pnltl.Top + 2
            .Height = pnltl.Height - 4
            .Width = pnltl.Width - 4
            .BackColor = Color.DimGray
            .FormBorderStyle = Windows.Forms.FormBorderStyle.None
            .Cursor = Cursors.Hand
            .AutoScroll = True
        End With
 
        ReDim tWin(800)
 
        WinHost.SuspendLayout()
        For I = 0 To UBound(tWin)
            tWin(I) = New ThumbnailWindow(My.Resources.Axis_320x180_6034e_thumb, String.Empty)
            tWin(I).Parent = WinHost
            tWin(I).Picture = My.Resources.Axis_320x180_6034e_thumb
            tWin(I).Location = New System.Drawing.Point((I * 128) + 3, 2)
            tWin(I).DayAndTime = I.ToString & " " & tWin(I).Left.ToString
            WinHost.Controls.Add(tWin(I))
        Next
        WinHost.ResumeLayout()
        WinHost.Refresh()
        WinHost.BringToFront()
        WinHost.Visible = True
        MsgBox("Done")
 
    End Sub
 
    Private Sub btnMakePanels_Click(sender As System.Object, e As System.EventArgs) Handles btnMakePanels.Click
        MakeTimeline()
    End Sub
 
    Private Sub btnBegin_Click(sender As System.Object, e As System.EventArgs) Handles btnBegin.Click
        With WinHost
            .ScrollControlIntoView(tWin(0))
        End With
    End Sub
 
    Private Sub btnEnd_Click(sender As System.Object, e As System.EventArgs) Handles btnEnd.Click
        WinHost.ScrollControlIntoView(tWin(UBound(tWin)))
    End Sub
End Class
 

The wxc.thumbnailwindow object is a simple custom control that I made. Sorry I can't share it here because it is the IP of my employer - suffice to say it is just a very simple control made up of a panel, a picturebox and a label. I created this for simplicity. You could make the same thing without creating a custom control.
The only problem I run into now is that there is a limit to the number of Handles Windows will allow (~2000) - but I'm not worried about that limit for my application.
I should also explain that pnltl is a panel control that I put on the form as a placeholder for the new control (the one made from system.forms.form). I did this so there isn't a big empty space to stare at before the timeline is made. It also provides the dimensions and a pretty border for my final control.
The result is great and looks exactly the way I want. There are also plenty of scroll events and methods to give me programatic control.

float mouse over image to see the whole thing
The thumbnails above each show the thumbnail number and the .left property - so you can see it goes well above the 32767 allowed by the wimpy panel control.
Yay.