racha3l ,
Please try the following two examples and get back to me.
First:
<%@ Page language="c#"%>
<%@ Register Namespace="CuteWebUI" Assembly="CuteWebUI.AjaxUploader" TagPrefix="CuteWebUI" %>
<html>
<head>
</head>
<body>
<form id="Form1" method="post" runat="server">
<CuteWebUI:Uploader runat="server" ID="Uploader1">
</CuteWebUI:Uploader>
</form>
</body>
</html>
Second:
<%@ Page language="c#"%>
<%@ Register Namespace="CuteWebUI" Assembly="CuteWebUI.AjaxUploader" TagPrefix="CuteWebUI" %>
<html>
<head>
</head>
<body>
<form id="Form1" method="post" runat="server">
<CuteWebUI:Uploader runat="server" ID="Uploader1">
<ValidateOption MaxSizeKB="10240" />
</CuteWebUI:Uploader>
</form>
</body>
</html>