compiling against MSVCP70.dll instead of MSVCP80.dll in Visual Studio 2005

Question

I am building a project in Visual Studio 2005 that require some libraries that were built in Visual Studio 2003. I'm getting linker errors like

msvcprt.lib(MSVCP80.dll) : error LNK2005: class std::basic_string[...]already defined in libdiguy.lib(bdiNavMesh.obj)

I believe that my program and the libraries are both compiled dynamically instead of statically. I've also tried changing the /MD and /MDd options because that seemed to be the solution to similar errors. My best guess at the moment is that it needs to link against MSVCP70.dll instead of MSVCP80.dll to resolve these errors. Is there a way I can compile against the older dll to see if that will fix it?

Thank you!