git-cvsimport and git-checkout problem

Greetings,

I'm learning git and decided to try importing a small CVS module
into a git repository (before attempting a really big one).
Existence of -i in git-cvsimport would seem to imply that it
checkouts by default but it didn't seem to do that.  That is, I did
"git-cvsimport -d ~/.cvs_root -C module module" and I got a
"module" directory that contains ".git" directory but nothing else.
And saying "git checkout master" in "module" doesn't seem to do
anything.

Finally I realized to try "git-checkout -f master" and that
worked.  By reading git-checkout(1) I just cannot see why -f was
needed in this case or even what it generally does ("re-read of
everything" -- um, what everything and why would you explicitly
want to re-read that everything?).

I'm using git 1.4.4.3 and cvsps 2.1 (from a git repository
recommended by some web page) on Debian GNU/Linux.

-- 
Hannu