I have not seen such behavior before.
Try deleting the CSSFormBuilder folder and adding a form again.
I don't think the problem is related to CSS Form Builder.
I would make a copy of that folder to not loose any information.
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.