Did you ever get a solution to this question?
I presume some CSS magic will be required! If so, if there has been anyone who has been successful in getting the submenu to display horizontally, we'd love to hear from 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.