I now activated the captcha questions plugin because the captcha images doesn't work correctly in 6.7.6. And I have some suggestions for this plug in:
It should have the option in the settings to work for trackbacks too. So I can get the TB link after answered question.
Multi language: the viewer should have the option to change the language for the question - e.g. german as standard and english as option. So in the settings I should have a text field for every language I chose.
A reload button for the question. If I don't understand the question, I should have the possibility to reload a new question I can answer (hopefully ).