Submodules and branches

I've got a repository that uses submodules. If I cd to the repo root and create a branch, all the submodules are switched to that branch as well. All good so far. I go into the submodules and do my work, committing as I go along. Then when I'm all done and want to merge the changes into my master branch, I cd back to the repo root and do "git merge new_topic"

That's where it breaks down. The commits that I made go into the master repo itself, and the submodules don't have them. So when I push from the submodule to its origin, nothing goes through. The code is now a part of the master repo.

Is it possible for me to use branches like usual, but with submodules?

Pat