I don't know if it's a feature, but tickets are not editable.
Confirmed. It might be possible to change this for each project (using tool permissions) but I think the default behaviour is to prevent the creator from editing (at least parts of) the original ticket: the owner and status are usually filled in by the developers.
Playing a bit with this, and it seems it is not possible to allow a user to edit just his own tickets. I always end up allowing the user to edit all tickets.
To me this makes since, I wouldn't want my reporters to go around editing their own tickets (e.g. re-opening the ones I closed, or closing).
So, its a feature :D, I'm closing this as wont-fix.