I have simplified the repeater to its bare bones and posted it in hope that you can replicate the problem. To be exact it happens on Chrome and mine is Version 31.0.1650.57 for XP. But it could e on other's versons too.
http://netsetix.com/WebForm1.aspx
So please open this link in Chrome and Add to cart say at least 3 items (it is not real DB driven adding). Then go either Forward or Backward with browser's buttons. Then get back to this page, again with browser's buttons and click on any of the items you previuosly clicked. The problem - all messages on all previuosly clicked items pop at once.
The code
<!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>Sample of the Ajax repeater problem. Standart button</title>
<link href="~/Styles/naviga.css" rel="stylesheet" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<h1>Sample of the Ajax repeater problem. Standart button</h1>
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server"><ContentTemplate>
<asp:Repeater ID="rptFashion" runat="server" EnableTheming="False">
<ITEMTEMPLATE>
<div class="rep_wrapper">
<div class="rep_leftCol"><h2><%# CType(Container.DataItem, System.Data.DataRowView)("product_name")%> </h2>
<asp:Literal ID="ltlAdded" runat="server" Text='<%# CType(Container.DataItem, System.Data.DataRowView)("item_added_message") %>'></asp:Literal></div>
<div class="rep_rightCol"><asp:Button runat="server" Text="Add To Cart" CommandName="bottonAdd" CssClass="buttonWidth" /></div>
<div class="clearBoth"></div></div>
</ITEMTEMPLATE>
</asp:Repeater>
</ContentTemplate></asp:UpdatePanel>
</form>
</body>
</html>
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
column = New DataColumn
column.DataType = System.Type.GetType("System.String")
column.ColumnName = "product_name"
dt_source.Columns.Add(column)
column = New DataColumn
column.DataType = System.Type.GetType("System.String")
column.ColumnName = "item_added_message"
dt_source.Columns.Add(column)
Dim i As Integer = 0
For i = 1 To 4
custrow = dt_source.NewRow()
custrow("product_name") = "Product " & i.ToString
custrow("item_added_message") = ""
dt_source.Rows.Add(custrow)
Next i
rptFashion.DataSource = dt_source
rptFashion.DataBind()
End If
End Sub
Protected Sub rptFashion_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.RepeaterCommandEventArgs) Handles rptFashion.ItemCommand
If (e.CommandName = "bottonAdd") Then
Dim frontMessage As Literal = CType(e.Item.FindControl("ltlAdded"), Literal)
frontMessage.Text = "<p class=""congrad"">Item Added To Cart</p>"
End If
End Sub