This usually happens when Bugzilla is unable to send an e-mail for the first change. If you can reproduce this error, then we can fix it (i.e. find out why the e-mail is not being sent the first time). If you cannot reproduce, there is nothing we can do to fix this issue.

(In reply to comment #1)
> This usually happens when Bugzilla is unable to send an e-mail for the first
> change. If you can reproduce this error, then we can fix it (i.e. find out
> why the e-mail is not being sent the first time). If you cannot reproduce,
> there is nothing we can do to fix this issue.

In that case I believe the old change should be simply discarded instead of sending bogus information.  The fact that bugzilla is blaming me for things I never did makes me slightly uneasy.

This is another example:

https://bugzilla.redhat.com/show_activity.cgi?id=921000


    Miroslav Franc <mfranc> changed:

               What    |Removed                     |Added
    ----------------------------------------------------------------------------
                     CC|ykaul            |
                     CC|                            |mfranc

I only added myself to CC.

In the see also bug, we will fix the e-mails so that even when we send multiple e-mails, they will have separate headers for each person making the change. The e-mail headers will still only refer to the person making the last change.

This change is now live. If there are any issues, do not reopen this bug.
Instead, you should create a new bug and reference this bug.

  -- simon