Unable to convert a subversion repo to git

I am seeing the following output while converting a subversion repo to git.

 >Found possible branch point: <repo-url>/trunk =>
<repo-url>/branches/CMT_PHASE3, 18441

fatal: Not a valid object name refs/remotes/BlueSimViewer 5.0 20110316 Branch
cat-file commit refs/remotes/BlueSimViewer 5.0 20110316 Branch: command returned error: 128

The command I am running to convert the repo is

git svn clone <repo-url> -A authors-transform.txt --stdlayout bluebox-git > svnlist

I am running git version 1.8.1.1 on an Ubuntu 12.10 server. I am happy
to provide any other information that would be helpful.

I appreciate any assistance you can provide in this matter,
  -Tim