Not sure if this functionality has been fixed, or is indeed intentional, but I thought I'd raise it in case it was an oversight.
Our project's workflow does not allow editing of closed issues. However, when deleting a version, the system told me there was 1 issue to be fixed for that version, and offered me the chance to change the version for that issue. However, it was a closed issue, so I shouldn't really be able to change the version on a closed issue. I wonder if this is intentional so administrators don't get stuck?