I found a bug that hard coded English string "Please select" is displayed at the selection of issue watchers on a issue form, and tried to fix it like this.

h4. Now

(redmine/app/views/watchers/_watchers.rhtml :20)

<%= f.select :user_id, (watched.addable_watcher_users.collect {|m| [m.name, m.id]}), :prompt => true %>

h4. ->Revised (redmine/app/views/watchers/_watchers.rhtml :20)

<%= f.select :user_id, (watched.addable_watcher_users.collect {|m| [m.name, m.id]}) %>

or maybe

<%= f.select :user_id, (watched.addable_watcher_users.collect {|m| [m.name, m.id]}), :prompt=>l(:label_please_select) %>

Regards