how to add file to a module

[Terrence Enger]

Greetings.

I started with
  - a repository,
  - a module definition listing specific files,
  - a sandbox into which I have checked out that module.

Then, a vendor update (cvs import) adds a new file to the repository.  Upon
examination, I decide that the new file should be part of the module I am
talking about, and I update the modules file accordingly.  

What should I do to get a copy of that file in my sandbox?  Some
possibilities that come to mind ...
  - "cvs update" does not add the file.  Naturally, because my sandbox has
CVS/Entries.Static.
  - "cvs update -d" adds lots more files which are still not part of the
module. 
  - "cvs checkout filename" tells me "cvs server: cannot find module
`filename' - ignored"
  - From one level up in the directory tree, "cvs checkout
modulename/filename" tells me "cvs server: module `modulename/filename' is
a request for a file in a module which is not a directory.
  - Delete the sandbox and check out the module again.  I think this would
work, but I must not have any uncommitted changes.  

I fear that I am overlooking something very basic.

Thank you, all, for your help.

Terry.
iSeries programmer, available for contract programming.