Depending on the type of object, you may not be able to restore to a previous release. For example, certain programs may use new functions that are not supported on a previous release. You will normally see error messages in the joblog when you try to save these objects for a previous release.
It sounds to me that what you’re doing is correct, you should only need to specify the target release. Check the joblog for the job when you do the save and again when you do the restore – there may be some other problem stopping you restoring – for example an authority problem.