In DreamWever CS3 Menu, go to Edit > WebAssist Preferences > Choose 'Memento' from the options on the left > Select 'Never' from the select list on the right.
That should do it.
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.