Unknown.rpt error while using Crystal report 7 and visual studio 2005

Hi all,
I have created a web application using Visual Studio 2005, Sql Server 2005 and crystal report 7 for reporting which is working fine on our companies’ test server but it is giving me error in my client’s web server. The error is Unknown.rpt : Report cannot be submitted to background process. I don’t know why it is me such error, while it is working fine on our companies web server? What could be the problem? Please Reply me soon…