The Preset Manager is under the WebAssist Menu.
if you continue to have a problem, please post back details about other extensions that are installed, including the version numbers.
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.