Bulk move of issue type creates duplicate entries in Change History

Bulk move one or more bugs from one issue type to another. There will be two entries for issue type in the change history tab and likewise two entries in the changeitem table in the database, one recorded as field=issue type and one recorded as field=type.
Also see my comment here: http://jira.atlassian.com/browse/JRA-17273?focusedCommentId=168071&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#action_168071