Insecure operation `[]' at level 4 (SecurityError)

/home/okamura/www/diary/tdiary.rb:436:in `[]'
/home/okamura/www/diary/tdiary.rb:72:in `join'
/home/okamura/www/diary/tdiary.rb:72:in `safe'
/home/okamura/www/diary/tdiary.rb:654:in `eval_src'
/home/okamura/www/diary/tdiary.rb:901:in `do_eval_rhtml'
/home/okamura/www/diary/tdiary.rb:851:in `eval_rhtml'
index.rb:67