Intellisense with single source file in multiple projects

In a single solution, if I have the same source file present in multiple projects (with different开发者_Python百科 project settings, e.g. different #defines), Intellisense and all the features depending on it seems to arbitrary pick one of the project settings when I edit the source file.

How do I get Intellisense to switch which project settings it uses for that file ?

If that is not possible, it would be at least useful to know which project Intellisense picks ?

I have exactly the same problem using VS2005. I read a while back that Microsoft found this to be 'intended functionality' and would not sort this out.

It seems that intellisense uses the first loaded project of the solution to apply the #defines for.