Bom Dia Douglas,
Thanks for coming back to us so soon, however I am still a little confused by your answer
Looking at the captcha.php file here, line 204 contains the following:
final class CaptchaMoovur extends Moovur {
(I have uploaded a copy of the file so that you can look at it)
Also I am not sure what you mean by the php being appended instead of replaced? Could you perhaps explain further?
For extra information, the fault that occurs (when CAPTCHA is enabled) is that as soon as you request the "contact" page from anywhere on the site, the site crashes with the error as previously mentioned.
The entire site is then inaccessible until CAPTCHA is disabled in the Joomla backend.
Regards
Alistair.