Can I/should I version my private project settings?
No. NetBeans 5.x and later CVS integration creates a .cvsignore file for private project settings (nbproject/private), so they are prevented from being committed to the repository. This helps to eliminate merge conflicts in projects shared by multiple users. Your project's build directories are also excluded.
NetBeans 4.x does not create an actual .cvsignore file for you (you should do this yourself if you are also using another CVS client) but will nonetheless skip over these files when performing CVS operations on the project.
Technical note for module developers: implemented by SharabilityQuery.