Stop Spambot Extension

I tried using the stop spambot extension.  The problem is once the user register and logins he/she is unable to post msg due to the program continuously asking the same question over and over again.  My test show that code is not recognizing the answer when the user is trying to post msg for the first time.  I uninstalled the extension and for now I'm using the valid email registration feature to minimize the activities of spambots.