Thread:Project:Support desk/ConfirmEdit/QuestyCaptcha works - but only with trigger "createaccount"

I'm managing a small musicological wiki (http://liturgica-notata.wiki.gwdg.de) and trying to keep it spamfree. I've installed several extensions, and the most effective so far seems to be QuestyCaptcha with some really special questions.

What bothers me is: QuestyCaptcha seems to be only triggered by "createaccount", though in the LocalSettings.php I have specified it to be triggered by "edit", "create", "createtalk", "addurl", "createaccount" und "badlogin"; "skipcaptcha" is "false" for "*" und "user" and true for "autoconfirmed". As an unregistered user, I can create and edit articles and talk-pages without captcha ("addurl" and "badlogin" I didn't try out).

What can be the cause for that funny behavior? And how can I change this? As all spammers in my wiki so far did create accounts, it is no serious problem, but I'd like to protect the other kinds of actions as well.

(I moved this question from Thread:Extension talk:ConfirmEdit/QuestyCaptcha works - but only with trigger "createaccount" since that page seems to be rather inactive.)