Subtasks are not displayed in the Release Notes

The documentation states "The release notes contain all issues within the specified project that are marked with a specific "Fix For" version". It seems this statement is not correct. Subtasks (which afaik are mostly handled and saved in the db like issues) are not shown when i use the standard release notes-template, although they are marked with the selected "fix for"-version. the parent issue gets displayed properly.
parent and subtasks have different "fix for"-versions.
The subtasks are properly displayed in filters (searching only with "fix for") and in the road map. This bug seems to be releated to JRA-5329.

We use the release notes to communicate with our clients, so it is now rather embarrassing to tell them it is not reliable. Is there a quick fix available i didn't see ?