Hangs on pull

First off, very eloquent solution you've developed...  I'm trying to pull a directory recursively from a ftp server and it's doing some work and then hanging.

```
ftp = FtpSync.new '0.0.0.0', 'user', 'password', :passive => true
ftp.pull_dir 'local_path', 'remote_path'
```

I have tried with and without passive... both hang indefinitely.  Any suggestions?

Don
