No permission to commit branch changes

[Sam]

Hello,

I have a little problem with commiting changes to a newly created CVS
branch:

-------
$ cvs ci -r mybranch program
cvs [server aborted]: "commit" requires write access to the repository
cvs commit: saving log message in /tmp/cvsByvIbK
-------

Of course, I have write permissions to the repository. In fact, creating
the new branch with rtag worked fine.
Will I have to set additional permissions to be able to commit changes
to the new branch or something?

Thank You!
-Samuel