Ошибка при добавлении слова в словарь

[ck3g]

$ ./word -a frenzy: безумие, бешенство
/home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/csv.rb:89:in open': 'mode' must be 'r', 'rb', 'w', or 'wb' (ArgumentError) from ./lib/db_words.rb:27:inadd'
from ./word:19
from /home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/optparse.rb:1298:in call' from /home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/optparse.rb:1298:inparse_in_order'
from /home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/optparse.rb:1254:in catch' from /home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/optparse.rb:1254:inparse_in_order'
from /home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/optparse.rb:1248:in order!' from /home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/optparse.rb:1339:inpermute!'
from /home/ck3g/.rvm/rubies/ree-1.8.7-2011.03/lib/ruby/1.8/optparse.rb:1360:in `parse!'
from ./word:57