The inertia project's CVS data is in read-only mode, so the project may have switched over to another source-code-management system. To check, visit the Project Summary Page for inertia and see if the menubar lists a newer code repository, such as SVN or Git.
The CVS data can be accessed as follows. You can run a per-module CVS checkout via pserver protocol:
You can view a list of files or copy all the CVS repository data via rsync (the 1st command lists the files, the 2nd copies):
If you are a project admin for inertia, you can request that this page redirect to another repo on your project by submitting a support request.