Solution loses project references when libraries are added to package

I have a SharePoint 2010 solution with four projects:

1. Company.SharePoint – class library project, not a SharePoint project, just reusable utilities with SharePoint references
2. Company.SharePoint.Data – same as #1, references #1
3. Company.SharePoint.Analytics – same as #1, references #1 & #2
4. Company.Product – SharePoint 2010 project, references #1, #2 & #3

Everything’s working well until packaged. By default, deploying Company.Product will not put the referenced projects in the GAC. If I edit the package -> Advanced -> Add the three libraries for GAC deployment, package works great, libraries go in the GAC as expected.

The Issue: After a successful build, I open a class in library #3, it’s as if I deleted the reference to #1 & #2. None of the intellisense works, errors show in error window, etc. If I go to a class in #4, right click a method pointing to #3, it takes me to the metadata view instead of the actual class. However, it all builds fine.

If I remove #’s 1 – 3 from the package, the issue goes away. Then, add them back to the package, the issue is back. I’ve recreated all the projects, all have same target platforms, etc. with no luck.

I’d love it if someone has a fix, or, if you’ve seen this, let me know. Thanks!