Rails analyze issue

hi all:
when i debug my site with Rails Analyzer
#------------------------------------------------------------------------
pl_analyze show me this:
pl_analyze /wwwroot/railsprojects/log/production.log
/usr/local/lib/ruby/gems/1.8/gems/production_log_analyzer-1.3.0/lib/production_log/analyzer.rb:381:in
pad_request_name': undefined method -’ for nil:NilClass
(NoMethodError)
#--------------------------------------------------------------------------
and crawl also not works.
crawl -u http://192.168.1.3/ -c
/usr/local/lib/ruby/gems/1.8/gems/rails_analyzer_tools-1.1.0/lib/analyzer_tools/crawl.rb:127:in
extract_url_from': private method scan’ called for nil:NilClass
(NoMethodError)
#--------------------------------------------------------------------------
my ruby is 1.8.4
something missed?