You only have required validation set for the CAPTCHA, not Like Entry validation, which is required to check they are both the same.
I've gone ahead and added the server validation for you.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.