Capistrano authentication to server fails but ssh for deploy user works

Capistrano authentication to server fails but ssh for deploy user works

I've been working with capistrano for about a year deploying an app and
everything went fine, until a couple of days ago when I got this
** [server_name :: out] fatal: Authentication failed
after typing deploy user's password. Trying to ssh using the same
credentials works perfectly.
Do you have any idea about what could have caused this? I'm using
capistrano (2.15.5) and ruby 1.9.3, and this is my Capfile:
load 'deploy' if respond_to?(:namespace) # cap2 differentiator
# Uncomment if you are using Rails' asset pipeline
# load 'deploy/assets'
Dir['vendor/gems/*/recipes/*.rb','vendor/plugins/*/recipes/*.rb'].each {
|plugin| load(plugin) }
load 'config/deploy' # remove this line to skip loading any of the default
tasks
default_run_options[:pty] = true
Thanks a lot!