JCaptcha does not seem to work in a clustered environment, since the Service must be a Singleton (as stated in JCaptcha's documentation).
In a cluster, it is possible for any captcha image to be generated by one server, and the response to be validated by an entirely different server, thus resulting in a CaptchaServiceException. As such, for any webapp deployed in a cluster, there exist as many captcha services as there exist servers with this app deployed in it.
Are there any plans to support clusters in JCaptcha? This is a show stopper for us, and will switch to another captcha technology if no support is available in the short term.
Integrated with Spring 2.0.7. Bug detected in Apache Tomcat 5.5.x and Weblogic 9.2.x clusters.