Sub-tasks excluded from HTML release notes

Steps to reproduce:

1. In 'Released Board', view the Release Notes of a version
2. In the next screen, choose to 'Include Sub-Tasks'
3. Switch to 'Preview HTML' tab. Sub-tasks are displayed fine
4. Visit the permalink of the view (by clicking on the chain icon). Sub-tasks are now gone

Example URL: http://myjira/secure/RunPortlet.jspa?portletKey=com.pyxis.greenhopper.jira:greenhopper-releasenotes&projectid=10000&fields=&versionId=10000&includeSubs=false

Toggling 'includeSubs' to 'true' does not make any difference either.