git-svn clone -s fails to setup branches in git if the most recent svn commit was not to trunk

I ran the following command to clone from an svn repository that followed the standard svn folder layout and had two branches:

svn clone -s svn://path/to/my_repo

I then typed:

git branch -r

Which returned:

origin/HEAD origin/master

I was expecting to see the branches and tags from the svn /branches and /tags folders but they did not appear.

I checked out origin/HEAD and origin/master to see what was there and I found they contained code from a subversion branch that was originally in the /branches folder. I noticed that this particular branch was the last place committed to in the svn repo. So I checked something into the /trunk of the svn repo, nuked the git repo, and ran the git svn clone command again. This time it worked as expected and "git branch -r" showed me all my tags and branches.