Redmine

I have a problem with email reminders 1.4.1,
root@management://usr/share/redmine-1.4# rake redmine:send_reminders days=7 RAILS_ENV="production" --trace
(in /usr/share/redmine-1.4)
Please install RDoc 2.4.2+ to generate documentation.

• Invoke redmine:send_reminders (first_time)
• Invoke environment (first_time)
• Execute environment
• Execute redmine:send_reminders
  rake aborted!
  can't convert Date into String
  /usr/share/redmine-1.4/app/models/mailer.rb:354:in `+'
  /usr/share/redmine-1.4/app/models/mailer.rb:354:in `reminders'
  /usr/share/redmine-1.4/lib/tasks/reminder.rake:40
  /usr/share/redmine-1.4/app/models/mailer.rb:381:in `with_synched_deliveries'
  /usr/share/redmine-1.4/lib/tasks/reminder.rake:39
  /usr/lib/ruby/1.8/rake.rb:636:in `call'
  /usr/lib/ruby/1.8/rake.rb:636:in `execute'
  /usr/lib/ruby/1.8/rake.rb:631:in `each'
  /usr/lib/ruby/1.8/rake.rb:631:in `execute'
  /usr/lib/ruby/1.8/rake.rb:597:in `invoke_with_call_chain'
  /usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
  /usr/lib/ruby/1.8/rake.rb:590:in `invoke_with_call_chain'
  /usr/lib/ruby/1.8/rake.rb:583:in `invoke'
  /usr/lib/ruby/1.8/rake.rb:2051:in `invoke_task'
  /usr/lib/ruby/1.8/rake.rb:2029:in `top_level'
  /usr/lib/ruby/1.8/rake.rb:2029:in `each'
  /usr/lib/ruby/1.8/rake.rb:2029:in `top_level'
  /usr/lib/ruby/1.8/rake.rb:2068:in `standard_exception_handling'
  /usr/lib/ruby/1.8/rake.rb:2023:in `top_level'
  /usr/lib/ruby/1.8/rake.rb:2001:in `run'
  /usr/lib/ruby/1.8/rake.rb:2068:in `standard_exception_handling'
  /usr/lib/ruby/1.8/rake.rb:1998:in `run'
  /usr/bin/rake:28
  root@management://usr/share/redmine-1.4#

do you have idea, what wrong?