In Dreamweaver CS4, go to Commands -> Manage Extensions. Are SecurityAssist and Cookies Toolkit listed in the extesnion manager? Is there a check mark in the enabled column for both of them?
If so, they should be available under the Insert menu: Insert -> WebAssist - Security Assist and Insert -> WebAssist -> Cookies Toolkit.
If you continue to have problems, please post screen shots of the Extension manager and insert menu.