Has anyone heard about vb code not working "properly" on Windows Server 2003 operating system?

I have an application that will work as i want it to on different computer all using XP Pro as the ooperating system

Then i tested it on two different Window Server 2003 machines and it works it just doesn't give the result it should and as it does for the XP Pro operating system?

I am wondering if this is a know bug or if there is a fix for either . NET 2003 or for the server operating system.

Thanks
Tricia