This plugin allows you to disable the update notification tasks when changing status with option "Issue Closed".
Just go to the management of your account and disable the notification.
Disable notifications for all type of the user: the authors, performers and observers.
Tested with Redmine 1.3.0 and Redmine Close Issue button https://github.com/Undev/redmine_close_button
Download the sources and put them to your vendor/plugins/redmine_notice folder.
cd {REDMINE_ROOT}
git clone git://github.com/parshukovvv/redmine_notice.git vendor/plugins/redmine_noticeRestart Redmine.