Jenkins running on Windows and trying to start OS X (10.8.2) slave via ssh (using private key)

LOG:

[03/18/13 17:45:56] [SSH] Opening SSH connection to 192.168.1.35:22.
[03/18/13 17:45:56] [SSH] Authenticating as Jenkins with C:\Jenkins\ssh_keys\private.ppk.
ERROR: Unexpected error in launching a slave. This is probably a bug in Jenkins.
java.lang.NegativeArraySizeException
at org.kohsuke.putty.KeyReader.read(KeyReader.java:59)
at org.kohsuke.putty.KeyReader.readInt(KeyReader.java:71)
at org.kohsuke.putty.PuTTYKey.toOpenSSH(PuTTYKey.java:198)
at hudson.plugins.sshslaves.SSHLauncher.openConnection(SSHLauncher.java:730)
at hudson.plugins.sshslaves.SSHLauncher.launch(SSHLauncher.java:278)
at hudson.slaves.SlaveComputer$1.call(SlaveComputer.java:222)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
[03/18/13 17:45:56] [SSH] Connection closed.