[TYPO3] captcha not functioning

[typo3 at gcnpublishing.com]

Hi,

I have used sr_freecap extension along with ve_guestbook extension. i
configured everything correctly. (it's simple) and the captcha shows up in
the blog input form. But, the captcha isn't working. it doesn't checks the
value being inputed and lets everything straight through. i looked in
every place but couldn't find anything wrong. Same thing works on another
site just fine. could anyone point what could be the issue.

Thanks,

Sundeep