pushing changes to a remote branch

Hi list,

I am using git-remote to clone a remote repository and track only a select number of branches:

  git remote add -f -t vim -t ssh origin git://git.server.org/path/to/repo.git
  git branch -r
    origin/ssh
    origin/vim
  git merge ...

I now merge these into the local repo and decide that I need to make a change to origin/vim. So I figure that it's probably easiest if I just checkout the remote branch, make the change, commit it, push it, return to the master branch, git-remote update and merge, but:

  git checkout origin/vim
    Note: moving to "origin/vim" which isn't a local branch
  echo change > newfile; git add newfile
  git commit -m'make change'
    Created commit 64b8b2e: make change
     1 files changed, 1 insertions(+), 0 deletions(-)
      create mode 100644 newfile
  
If I now checkout master and then return to origin/vim, the commit
is gone.

If I repeat all this and, instead of returning to master, I push the commit to origin, git suggests success (the push looks normal). However, I then cannot find the commit anymore. It's not available locally, nor in origin/vim, nor in the local master branch or in origin/master.

This is curious and I'd love to find out what's going on.

Much more, however, I am interested how I am supposed to push commits back to select remote branches.

Using

  git push git://git.server.org/path/to/repo.git \
    7fbb0655:refs/heads/vim

does push commit 7fbb0655 to the vim branch in the remote repository, but I should be able to do this using origin/vim, no? How?