Compatibility issue between Microsoft Visual Studio 2005 and Microsoft Visual Web Developer 2010 Express

Question

Hello,

I have a web application that was originally written using Visual Studio 2005.

I have made some changes to one of the projects using Visual Web Developer 2010. This seems to create problems with the files created in Visual Studio 2005. I tried to rebuild the project in Visual Studio but when I open it, I loose references and if I try to add them again, the path to the file I want to reference is not created, making the reference invalid.

However, if I open the same project with Visual Web Developer, the references are fine.

How could I, if possible, make the project compatible with both IDEs?

Thank you.