title: hg doesn't connect to bitbucket using a custom key
body: <p>On my computer I have</p>
  
  <p>.ssh/config:</p>
  
  <pre><code>Host bitbucket
      HostName bitbucket.org
      User hg
      IdentityFile ~/.ssh/id_rsa_pwd  
  </code></pre>
  
  <p>.hg/hgrc</p>
  
  <pre><code>[paths]
  default = ssh://hg@bitbucket.org/lohoris/varlibs
  </code></pre>
  
  <p>(running OSX 10.6)</p>
  
  <p>I have exactly the same files on a debian server, but while "trying" a shell login works on both:</p>
  
  <pre><code>PTY allocation request failed on channel 0
  conq: logged in as lohoris.
  
                             You can use git or hg to connect to Bitbucket. Shell access is disabled.
                                                                                                     Connection to bitbucket.org closed.
  </code></pre>
  
  <p>mercurial connection only works on my computer, while from the server it refuses to cooperate:</p>
  
  <pre><code>lohoris@office:~/www/varlibs$ hg pull
  remote: Permission denied (publickey).
  abort: no suitable response from remote hg!
  </code></pre>
  
  <p>This is the same message you get when the key is wrong, only it is not wrong of course (as I said, trying a <code>ssh bitbucket</code> <strong>does work</strong>).</p>
  
  <p>It <em>is</em> likely using the wrong key, since it's not even trying to ask me the passphrase, but I can't fathom <em>why</em>.</p>