Oops, I typo'd on the command.  Here is the correct trace:

Sat 2011-04-23 22:12:50 -0400
0.145  bazaar version: 2.3.0
0.145  bzr arguments: [u'colo-fetch', u'colo:bzr+ssh://aloe.trausch.us/home/mbt/Projects/desktop/alltray:origin/trunk', u'alltray']
0.233  looking for plugins in /Users/mbt/.bazaar/plugins
0.233  looking for plugins in /Library/Python/2.6/site-packages/bzrlib/plugins
0.656  encoding stdout as sys.stdout encoding 'UTF-8'
0.760  creating repository in file:///Users/mbt/Projects/client/alltray/.bzr/branches/.bzr/.
0.770  creating branch <bzrlib.branch.BzrBranchFormat7 object at 0x1024e5c90> in file:///Users/mbt/Projects/client/alltray/.bzr/branches/origin/trunk/
0.852  creating branch reference in file:///Users/mbt/Projects/client/alltray/
0.865  trying to create missing lock '/Users/mbt/Projects/client/alltray/.bzr/checkout/dirstate'
0.865  opening working tree '/Users/mbt/Projects/client/alltray'
1.041  opening working tree '/Users/mbt/Projects/client/alltray'
1.469  bzr-svn: using Subversion 1.6.15 (), Subversion API 1.6.5 (), subvertpy 0.7.5
1.879  ssh implementation is OpenSSH
4.267  Traceback (most recent call last):
  File "/Library/Python/2.6/site-packages/bzrlib/commands.py", line 923, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/Library/Python/2.6/site-packages/bzrlib/commands.py", line 1123, in run_bzr
    ret = run(*run_argv)
  File "/Library/Python/2.6/site-packages/bzrlib/commands.py", line 691, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/Library/Python/2.6/site-packages/bzrlib/commands.py", line 710, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/Library/Python/2.6/site-packages/bzrlib/cleanup.py", line 135, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/Library/Python/2.6/site-packages/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/Library/Python/2.6/site-packages/bzrlib/plugins/colo/commands.py", line 278, in run
    remember=True)
  File "/Library/Python/2.6/site-packages/bzrlib/commands.py", line 710, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/Library/Python/2.6/site-packages/bzrlib/cleanup.py", line 135, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/Library/Python/2.6/site-packages/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/Library/Python/2.6/site-packages/bzrlib/builtins.py", line 964, in run
    possible_transports=possible_transports)
  File "/Library/Python/2.6/site-packages/bzrlib/bundle/__init__.py", line 39, in read_mergeable_from_url
    possible_transports=possible_transports)
  File "/Library/Python/2.6/site-packages/bzrlib/transport/__init__.py", line 1582, in get_transport
    base = directories.dereference(base)
  File "/Library/Python/2.6/site-packages/bzrlib/directory_service.py", line 58, in dereference
    return service().look_up(name, url)
  File "/Library/Python/2.6/site-packages/bzrlib/plugins/colo/colocated.py", line 142, in look_up
    return ColocatedWorkspace(url_piece).url_for_name(branch_name)
  File "/Library/Python/2.6/site-packages/bzrlib/plugins/colo/colocated.py", line 61, in __init__
    branch = a_bzrdir.open_branch()
  File "/Library/Python/2.6/site-packages/bzrlib/remote.py", line 349, in open_branch
    location=response[1], ignore_fallbacks=ignore_fallbacks)
  File "/Library/Python/2.6/site-packages/bzrlib/branch.py", line 2346, in open
    location, possible_transports=possible_transports)
  File "/Library/Python/2.6/site-packages/bzrlib/bzrdir.py", line 717, in open
    return BzrDir.open_from_transport(t, _unsupported=_unsupported)
  File "/Library/Python/2.6/site-packages/bzrlib/bzrdir.py", line 747, in open_from_transport
    redirected)
  File "/Library/Python/2.6/site-packages/bzrlib/transport/__init__.py", line 1670, in do_catching_redirections
    return action(transport)
  File "/Library/Python/2.6/site-packages/bzrlib/bzrdir.py", line 734, in find_format
    transport, _server_formats=_server_formats)
  File "/Library/Python/2.6/site-packages/bzrlib/controldir.py", line 754, in find_format
    raise errors.NotBranchError(path=transport.base)
NotBranchError: Not a branch: "/home/mbt/Projects/desktop/alltray/.bzr/branches/versions/0.7.5dev/".

4.267  Transferred: 0kB (0.0kB/s r:0kB w:0kB)
4.267  return code 3