Hello,
I have created a simple Callback panel and added a TreeView that loads data from a database.  
The code below is an example that fails only when the callback is initiated by the user when selecting the button to trigger the control and not at the pageload.  In this example I am trying to make it fail, but when I apply this code to my dataset, the number of records "Customers" --> orders, bills, etc.  fails at as little as 10 customers.  
What's interesting is when I remove the callback panel from the equation, then the code and the Treeview work fine and I can load over 100 customers.
Can you please help me resolve my issues?
    
        Code: HTML/ASPX
        
        <%@ Page Language="vb" AutoEventWireup="false" CodeBehind="TreeCallBackTest.aspx.vb" Inherits="WebSite.TreeCallBackTest" %>
<%@ Register Assembly="EO.Web" Namespace="EO.Web" TagPrefix="eo" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <eo:CallbackPanel ID="CallbackPanel1" runat="server" Height="150px" Triggers="{ControlID:Button1;Parameter:}" Width="200px">
            <eo:TreeView ID="SR" runat="server" AutoSelectSource="ItemClick" ControlSkinID="None" Height="250px" Width="200px">
                <LookNodes>
                    <eo:TreeNode DisabledStyle-CssText="background-color:transparent;border-bottom-style:none;border-left-style:none;border-right-style:none;border-top-style:none;color:Gray;padding-bottom:1px;padding-left:1px;padding-right:1px;padding-top:1px;" ItemID="_Default" NormalStyle-CssText="PADDING-RIGHT: 1px; PADDING-LEFT: 1px; PADDING-BOTTOM: 1px; COLOR: black; BORDER-TOP-STYLE: none; PADDING-TOP: 1px; BORDER-RIGHT-STYLE: none; BORDER-LEFT-STYLE: none; BACKGROUND-COLOR: transparent; BORDER-BOTTOM-STYLE: none" SelectedStyle-CssText="background-color:#316ac5;border-bottom-color:#999999;border-bottom-style:solid;border-bottom-width:1px;border-left-color:#999999;border-left-style:solid;border-left-width:1px;border-right-color:#999999;border-right-style:solid;border-right-width:1px;border-top-color:#999999;border-top-style:solid;border-top-width:1px;color:White;padding-bottom:0px;padding-left:0px;padding-right:0px;padding-top:0px;">
                    </eo:TreeNode>
                </LookNodes>
                <TopGroup Style-CssText="border-bottom-color:#999999;border-bottom-style:solid;border-bottom-width:1px;border-left-color:#999999;border-left-style:solid;border-left-width:1px;border-right-color:#999999;border-right-style:solid;border-right-width:1px;border-top-color:#999999;border-top-style:solid;border-top-width:1px;color:black;cursor:hand;font-family:Tahoma;font-size:8pt;padding-bottom:2px;padding-left:2px;padding-right:2px;padding-top:2px;">
                </TopGroup>
            </eo:TreeView>
        </eo:CallbackPanel>
         </div>
        <asp:Button ID="Button1" runat="server" Text="Button" />
    </form>
</body>
</html> 
 
    
        Code: Visual Basic.NET
        
        Partial Public Class TreeCallBackTest
    Inherits System.Web.UI.Page
    Protected Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then
            LoadTree(30)
        End If
    End Sub
    
    Protected Sub LoadTree(ByVal NumberofRecords As Integer)
        Dim str As String = String.Empty
        Dim CustomerNode As EO.Web.TreeNode
        Dim OrderNode As EO.Web.TreeNode
        Dim level3Node As New EO.Web.TreeNode
        Dim level4Node As New EO.Web.TreeNode
        SR.Nodes.Clear()
        Dim NodeID As Integer = -1
        For i As Integer = 0 To NumberofRecords
            'Add Customer to tree
            NodeID += 1
            CustomerNode = New EO.Web.TreeNode
            CustomerNode.Text = "Customer " & i
            CustomerNode.Value = "Customer_ID"
            CustomerNode.ItemID = NodeID
            CustomerNode.Selected = True
            CustomerNode.NormalStyle.BackColor = Drawing.Color.LightYellow
            For j As Integer = 0 To 10
                'Add order information
                NodeID += 1
                OrderNode = New EO.Web.TreeNode
                OrderNode.Text = "Order: Test"
                OrderNode.Value = "Order_ID"
                OrderNode.ItemID = NodeID
                For k As Integer = 0 To 10
                    NodeID += 1
                    level3Node = New EO.Web.TreeNode
                    level3Node.Text = "Bill"
                    level3Node.Value = "Billing_ID"
                    level3Node.ItemID = NodeID
                    level3Node.NormalStyle.BackColor = Drawing.Color.LightGreen
                    For L As Integer = 0 To 10
                        NodeID += 1
                        level4Node = New EO.Web.TreeNode
                        level4Node.Text = "Machine"
                        level4Node.Value = "Task_ID," & L
                        level4Node.ItemID = NodeID
                        level4Node.NormalStyle.BackColor = Drawing.Color.LightPink
                        level3Node.SubGroup.Nodes.Add(level4Node)
                    Next
                    OrderNode.SubGroup.Nodes.Add(level3Node)
                Next
                CustomerNode.SubGroup.Nodes.Add(OrderNode)
            Next
            SR.Nodes.Add(CustomerNode)
        Next
    End Sub
    Protected Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        LoadTree(25)
    End Sub
End Class