erro ao usar symbol

trace.txt

2013-02-27T17:48:24Z 19956 TID--9tjdlm Qe::Sidekiq::Worker JID-aa29bc17e817106ea5074e1d INFO: start
2013-02-27T17:48:24Z 19956 TID--9tjdlm Qe::Sidekiq::Worker JID-aa29bc17e817106ea5074e1d INFO: fail: 0.004 sec
2013-02-27T17:48:24Z 19956 TID--9tjdlm WARN: {"retry"=>true, "queue"=>"default", "class"=>"Qe::Sidekiq::Worker", "args"=>["MailerWorker", {"mail"=>"new_password_mail", "name"=>"Usuario", "email"=>"[email protected]"}], "jid"=>"aa29bc17e817106ea5074e1d", "error_message"=>"nil is not a symbol", "error_class"=>"TypeError", "failed_at"=>2013-02-27 17:48:24 UTC, "retry_count"=>0}
2013-02-27T17:48:24Z 19956 TID--9tjdlm WARN: nil is not a symbol
2013-02-27T17:48:24Z 19956 TID--9tjdlm WARN: /var/www/gvar/releases/20130226060346/app/services/mailer_worker.rb:5:in `public_send'
/var/www/gvar/releases/20130226060346/app/services/mailer_worker.rb:5:in `perform'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/qe-0.2.1/lib/qe/worker.rb:24:in `block in perform'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/qe-0.2.1/lib/qe/worker.rb:21:in `tap'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/qe-0.2.1/lib/qe/worker.rb:21:in `perform'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/qe-0.2.1/lib/qe/sidekiq.rb:10:in `perform'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/processor.rb:45:in `block (3 levels) in process'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:109:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:109:in `block in invoke'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/server/timeout.rb:14:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:111:in `block in invoke'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/server/active_record.rb:6:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:111:in `block in invoke'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/server/retry_jobs.rb:49:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:111:in `block in invoke'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/server/logging.rb:11:in `block in call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/logging.rb:22:in `with_context'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/server/logging.rb:7:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:111:in `block in invoke'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:114:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/middleware/chain.rb:114:in `invoke'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/processor.rb:44:in `block (2 levels) in process'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/processor.rb:80:in `stats'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/sidekiq-2.7.5/lib/sidekiq/processor.rb:43:in `block in process'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/celluloid-0.12.4/lib/celluloid/calls.rb:23:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/celluloid-0.12.4/lib/celluloid/calls.rb:23:in `public_send'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/celluloid-0.12.4/lib/celluloid/calls.rb:23:in `dispatch'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/celluloid-0.12.4/lib/celluloid/future.rb:18:in `block in initialize'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/celluloid-0.12.4/lib/celluloid/internal_pool.rb:48:in `call'
/var/www/gvar/shared/bundle/ruby/2.0.0/gems/celluloid-0.12.4/lib/celluloid/internal_pool.rb:48:in `block in create'