can't convert Fixnum into String (TypeError)

/usr/local/httpd/htdocs/mini/diary/tdiary.rb:1033:in `require'
/usr/local/httpd/htdocs/mini/diary/tdiary.rb:1033:in `load_filters'
/usr/local/httpd/htdocs/mini/diary/tdiary.rb:1032:in `load_filters'
/usr/local/httpd/htdocs/mini/diary/tdiary.rb:1047:in `referer_filter'
/usr/local/httpd/htdocs/mini/diary/tdiary.rb:1424:in `initialize'
/usr/local/httpd/htdocs/mini/diary/tdiary.rb:1498:in `initialize'
/usr/local/httpd/htdocs/mini/diary/index.rb:35