logstash regexp error

gistfile1.txt

D, [2012-11-02T18:24:04.320000 #29703] DEBUG -- : TRYING stanzacbs...
D, [2012-11-02T18:24:04.320000 #29703] DEBUG -- : TRYING message/iq/presence/cbs...
W, [2012-11-02T18:24:04.332000 #29703]  WARN -- : EXCEPTION:
    REXML::ParseException
    #<Encoding::CompatibilityError: incompatible encoding regexp match (UTF-8 regexp with ASCII-8BIT string)>
    org/jruby/RubyRegexp.java:1505:in `match'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/META-INF/jruby.home/lib/ruby/1.9/rexml/source.rb:212:in `match'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/META-INF/jruby.home/lib/ruby/1.9/rexml/parsers/baseparser.rb:369:in `pull'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/META-INF/jruby.home/lib/ruby/1.9/rexml/parsers/sax2parser.rb:92:in `parse'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/streamparser.rb:79:in `parse'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/stream.rb:75:in `start'
    ...
    Exception parsing
    Line: 
    Position: 0
    Last 80 unconsumed characters:
    <presence from='chefs@conference.im.blueboxgrid.com/Nesti Arène' to='logstash@im
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/META-INF/jruby.home/lib/ruby/1.9/rexml/parsers/baseparser.rb:441:in `pull'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/META-INF/jruby.home/lib/ruby/1.9/rexml/parsers/sax2parser.rb:92:in `parse'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/streamparser.rb:79:in `parse'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/stream.rb:75:in `start'
W, [2012-11-02T18:24:04.334000 #29703]  WARN -- : EXCEPTION:
    TypeError
    can't convert REXML::ParseException into String
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/stream.rb:136:in `parse_failure'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/streamparser.rb:81:in `parse'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/stream.rb:75:in `start'
W, [2012-11-02T18:24:04.335000 #29703]  WARN -- : Exception caught in Parser thread! (TypeError)
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/stream.rb:136:in `parse_failure'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/streamparser.rb:81:in `parse'
    file:/opt/logstash/server/lib/logstash-1.1.4.jar!/gems/xmpp4r-0.5/lib/xmpp4r/stream.rb:75:in `start'