I am not sure whether I am missing anything in my procedure, but I noticed a pretty bazzare behaviour in VS2005.
I have a Smart Device Cab Project in my solution.
The NOT working process:
I double click my solution to open Visual Studio 2005, when I right click my Smart Device Cab Project select add file, it will end up without adding the file to the project, but there is no error either.
The workaround process:
If I first open Visual Studio from start menu, then open my solution in VS2005, the adding file will work like a charm.
Similar thing will happen to Setup Project.
I am not sure whether I am missing anything.
BTW: I have ReSharper 2.0 installed on top of VS2005 Team suite.