Win32: The server's host key is not cached in the registry

Hello all,

Windows XP user here. Using PuTTy (and plink.exe) version 0.60. I was running an older version of Bzr (1.3 I believe), and all was well. I upgraded to 1.5 (Python 2.5 installer). Now all bzr+ssh operations fail with the following error:

Using last location: bzr+ssh://<email address hidden>/lighty/
The server's host key is not cached in the registry. You
have no guarantee that the server is the computer you
think it is.
The server's rsa2 key fingerprint is:
ssh-rsa 2048 01:e2:36:2b:17:7f:82:29:59:92:bd:e2:1d:15:28:24
Connection abandoned.
bzr: ERROR: Connection closed: please check connectivity and permissions (and try -Dhpss if further diagnosis is required)

Before I upgraded, managing host keys was as simple as adding a line to C:\Documents and Settings\user\Application Data\bazaar\2.0\ssh_host_keys. But this new version of bzr isn't even accessing ssh_host_keys (checked with FileMon.) And I have no idea where "the registry" is located. I have verified that C:\Documents and Settings\user\Application Data\bazaar\2.0\ssh_host_keys is updated and has the correct information.

Here's the traceback, in case it helps:

0.351 encoding stdout as sys.stdout encoding 'cp437'
0.361 bzr arguments: [u'missing', u'-v']
0.361 looking for plugins in C:/Documents and Settings/user/Application Data/bazaar/2.0/plugins
0.361 looking for plugins in C:\bin\Python25\lib\site-packages\bzrlib\plugins
0.361 Plugin name __init__ already loaded
0.361 Plugin name __init__ already loaded
0.871 encoding stdout as sys.stdout encoding 'cp437'
1.352 ssh implementation is Putty's plink.
2.484 Traceback (most recent call last):
  File "C:\bin\Python25\Lib\site-packages\bzrlib\commands.py", line 846, in run_bzr_catch_errors
    return run_bzr(argv)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\commands.py", line 797, in run_bzr
    ret = run(*run_argv)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\commands.py", line 499, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\commands.py", line 807, in ignore_pipe
    result = func(*args, **kwargs)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\builtins.py", line 3322, in run
    remote_branch = Branch.open(other_branch)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\branch.py", line 107, in open
    possible_transports=possible_transports)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\bzrdir.py", line 667, in open
    return BzrDir.open_from_transport(t, _unsupported=_unsupported)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\bzrdir.py", line 704, in open_from_transport
    redirected)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\transport\__init__.py", line 1616, in do_catching_redirections
    return action(transport)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\bzrdir.py", line 681, in find_format
    transport, _server_formats=_server_formats)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\bzrdir.py", line 1440, in find_format
    return format.probe_transport(transport)
  File "C:\bin\Python25\Lib\site-packages\bzrlib\bzrdir.py", line 2398, in probe_transport
    server_version = medium.protocol_version()
  File "C:\bin\Python25\Lib\site-packages\bzrlib\smart\medium.py", line 421, in protocol_version
    self._protocol_version = client_protocol.query_version()
  File "C:\bin\Python25\Lib\site-packages\bzrlib\smart\protocol.py", line 621, in query_version
    resp = self.read_response_tuple()
  File "C:\bin\Python25\Lib\site-packages\bzrlib\smart\protocol.py", line 544, in read_response_tuple
    result = self._recv_tuple()
  File "C:\bin\Python25\Lib\site-packages\bzrlib\smart\protocol.py", line 602, in _recv_tuple
    return _decode_tuple(self._recv_line())
  File "C:\bin\Python25\Lib\site-packages\bzrlib\smart\protocol.py", line 614, in _recv_line
    "(and try -Dhpss if further diagnosis is required)")
ConnectionReset: Connection closed: please check connectivity and permissions (and try -Dhpss if further diagnosis is required)

2.484 return code 3

Anyone know what I'm doing wrong? Thanks!