Error on "cap setup"

Capistrano is throwing an ugly error after SSH authentication with my application server on both 'cap setup' and 'cap deploy'. It's particularly strange because I haven't encountered this on any other projects, and am using a nearly identical (and near stock) deploy.rb file. Does this look familiar to anyone?

/opt/local/lib/ruby/gems/1.8/gems/net-ssh-1.0.10/lib/net/ssh/transport/packet-stream.rb:173:in `update': data must not be empty (ArgumentError)
         from /opt/local/lib/ruby/gems/1.8/gems/net-ssh-1.0.10/lib/net/ssh/transport/packet-stream.rb:173:in `get'
         from /opt/local/lib/ruby/gems/1.8/gems/net-ssh-1.0.10/lib/net/ssh/transport/packet-stream.rb:147:in `synchronize'
         from /opt/local/lib/ruby/gems/1.8/gems/net-ssh-1.0.10/lib/net/ssh/transport/packet-stream.rb:147:in `get'
         from /opt/local/lib/ruby/gems/1.8/gems/needle-1.3.0/lib/needle/lifecycle/proxy.rb:60:in `__send__'
         from /opt/local/lib/ruby/gems/1.8/gems/needle-1.3.0/lib/needle/lifecycle/proxy.rb:60:in `method_missing'
         from /opt/local/lib/ruby/gems/1.8/gems/net-ssh-1.0.10/lib/net/ssh/transport/session.rb:247:in `wait_for_message'
         from /opt/local/lib/ruby/gems/1.8/gems/net-ssh-1.0.10/lib/net/ssh/transport/session.rb:242:in `loop'
         from /opt/local/lib/ruby/gems/1.8/gems/net-ssh-1.0.10/lib/net/ssh/transport/session.rb:242:in `wait_for_message'
          ... 23 levels...
         from /opt/local/lib/ruby/gems/1.8/gems/capistrano-1.4.1/lib/capistrano/cli.rb:12:in `execute!'
         from /opt/local/lib/ruby/gems/1.8/gems/capistrano-1.4.1/bin/cap:11
         from /opt/local/bin/cap:16:in `load'
         from /opt/local/bin/cap:16