Here are the details of my problem:
I have a directory structure that looks like this:

where ios-srcare all my project and source code files, and ios-libsare all my git submodules.
When I clone a project to another computer, all the files in the ios-libs directory are displayed as red (or missing) in Xcode (v4.3.2), however the files are present on the disk.
If I delete files from Xcode and re-add them, it will NOT fix the problem, they are still red, and the project does not compile.
All directories are marked as Relative to Group.
If I select a file in the inspector, I get the following:

. ( ) , :

, ( ) . , ios-lib ios-src, , , .
, - , , , . , , . Lion XCode.
, , . , .