logstash split error

gistfile1.txt

{:timestamp=>"2013-12-10T20:59:56.794000+0000", :message=>"Exception in filterworker", "exception"=>#<TypeError: can't clone Fixnum>, "backtrace"=>["org/jruby/RubyKernel.java:2055:in `clone'", "file:/usr/local/logging/logstash/logstash-1.2.2-flatjar.jar!/logstash/event.rb:81:in `clone'", "org/jruby/RubyHash.java:1324:in `each'", "file:/usr/local/logging/logstash/logstash-1.2.2-flatjar.jar!/logstash/event.rb:79:in `clone'", "file:/usr/local/logging/logstash/logstash-1.2.2-flatjar.jar!/logstash/filters/split.rb:51:in `filter'", "org/jruby/RubyArray.java:1613:in `each'", "file:/usr/local/logging/logstash/logstash-1.2.2-flatjar.jar!/logstash/filters/split.rb:48:in `filter'", "(eval):2463:in `initialize'", "org/jruby/RubyProc.java:271:in `call'", "file:/usr/local/logging/logstash/logstash-1.2.2-flatjar.jar!/logstash/pipeline.rb:250:in `filter'", "file:/usr/local/logging/logstash/logstash-1.2.2-flatjar.jar!/logstash/pipeline.rb:191:in `filterworker'", "file:/usr/local/logging/logstash/logstash-1.2.2-flatjar.jar!/logstash/pipeline.rb:134:in `start_filters'"], :level=>:error}