Hi,
Change the Culture in Report.aspx to
<%@ Page language="c#" Codebehind="Report.aspx.cs" AutoEventWireup="false" Inherits="Microsoft.ReportingServices.UI.ReportWrapperPage" EnableEventValidation="false" Culture="en-GB"%>
Report.aspx file path :
C:\Program Files\Microsoft SQL Server\MSSQL.3\Reporting Services\ReportManager\Pages
