Redmine

When user has enabled option "I don't want to be notified of changes that I make myself"
RegexpError (invalid regular expression: /[l.bobkiewicz@it-partner.pl]+/):
/usr/lib/ruby/1.8/jcode.rb:153:in `delete!'
/usr/lib/ruby/1.8/jcode.rb:157:in `delete'
app/models/mailer.rb:394:in `create_mail'
/usr/lib/ruby/1.8/observer.rb:185:in `notify_observers'
/usr/lib/ruby/1.8/observer.rb:184:in `each'
/usr/lib/ruby/1.8/observer.rb:184:in `notify_observers'
app/models/journal.rb:47:in `save'
app/models/issue.rb:897:in `create_journal_without_description'
app/models/issue.rb:606:in `save_issue_with_child_records'
app/models/issue.rb:588:in `save_issue_with_child_records'
app/controllers/issues_controller.rb:176:in `update_without_check_spent_time'
public/dispatch.fcgi:24
shows up. When option is cleared everything is ok. Can You help me with issue?

./about
About your application's environment
Ruby version 1.8.7 (x86_64-linux)
RubyGems version 1.3.7
Rack version 1.1
Rails version 2.3.11
Active Record version 2.3.11
Active Resource version 2.3.11
Action Mailer version 2.3.11
Active Support version 2.3.11
Edge Rails revision unknown
Application root /VIRTUAL/WWW/vhosts/redmine
Environment development
Database adapter mysql
Database schema version 0