Error "The RDLC file is not a well-formed XML document"

Hello, I installed Microsoft Dynamics Nav 2009 and Visual Studio 2008 SP1.

For example, Object designer, report 101, design, click on View-Layout, something a couple of changes and when I close visual studio, I move to an empty line, get the message "The layout of report id: 101 is changed by another apllication .... Do you want to load the changes? pulse yes and then I get the error message "The RDLC file is not a well-formed XML document."

Can someone help me?

Thanks